Contacts of the helix formed by residues 13 - 42 (chain 2) in PDB entry 1CNT


Residue contacts within the protein are derived with the CSU software (Sobolev V., Sorokine A., Prilusky J., Abola E.E. and Edelman M. (1999) Automated analysis of interatomic contacts in proteins. Bioinformatics, 15, 327-332). A short description of the analytical approach is given at the end of the page.
For CSU analysis of other PDB entry

Note:
Non-standard 3 letter residue codes indicate a heterogroup. To identify and analyse, use LPC software

Legend:
Dist - nearest distance (Å) between atoms of two residues
Surf - contact surface area (Å2) between two residues
HB   - hydrophilic-hydrophilic contact (hydrogen bond)
Arom - aromatic-aromatic contact
Phob - hydrophobic-hydrophobic contact
DC   - hydrophobic-hydrophilic contact (destabilizing contact)
+/-  - indicates presence/absence of a specific contacts
*    - indicates residues forming contacts  by their side chain
       (including CA atoms)
Residues in contact with ARG 13 (chain 2).
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     122  HIS*     1.3    75.2    -      -       +      +
     142  ARG*     1.3    66.2    +      -       +      +
     162  LEU*     3.4     4.9    +      -       -      +
     172  CYS*     3.1    31.0    +      -       -      -
     692  GLU*     2.8    38.5    +      -       -      -
    1262  LEU*     4.2     1.6    -      -       +      +
    1292  LEU*     3.7    19.7    -      -       +      +
    1302  LEU*     4.0    21.8    -      -       +      +
    1792  ILE*     2.9    28.3    +      -       +      +
    1802  SER*     3.5    17.7    -      -       -      -
    1822  HIS*     3.5    12.5    -      -       -      +
    1832  GLN*     3.8    31.9    +      -       -      +
----------------------------------------------------------
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Residues in contact with ARG 14 (chain 2). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     122  HIS*     3.4    30.0    +      -       +      +
     132  ARG*     1.3    81.3    -      -       +      +
     152  ASP*     1.3    59.5    +      -       -      +
     172  CYS*     3.2     4.0    +      -       -      +
     182  SER*     2.8    33.1    +      -       -      +
    1802  SER*     3.6    34.4    +      -       -      +
    1812  SER*     3.7     6.6    -      -       -      +
    1842  THR*     2.9    33.7    +      -       -      +
    1862  ILE*     3.4    12.7    -      -       -      +
    1872  PRO*     3.1    40.8    -      -       -      +
----------------------------------------------------------
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Residues in contact with ASP 15 (chain 2). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     122  HIS*     3.1    36.1    +      -       +      +
     132  ARG      3.4     0.4    -      -       -      -
     142  ARG*     1.3    74.5    -      -       -      +
     162  LEU*     1.3    64.6    +      -       +      +
     182  SER*     3.2     9.8    +      -       -      -
     192  ARG*     2.9    33.2    +      -       +      +
----------------------------------------------------------
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Residues in contact with LEU 16 (chain 2). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     122  HIS      3.5    19.9    +      -       -      +
     132  ARG      3.4     4.4    +      -       -      +
     142  ARG      3.3     0.4    -      -       -      -
     152  ASP*     1.3    80.6    -      -       +      +
     172  CYS*     1.3    64.5    +      -       -      +
     192  ARG*     3.3    27.4    +      -       -      +
     202  SER*     3.0    27.1    +      -       -      -
    1222  GLN      5.0     1.1    -      -       -      +
    1252  GLU*     3.8    19.7    -      -       +      +
    1262  LEU*     3.5    46.4    -      -       +      +
    1292  LEU*     4.1    12.8    -      -       +      -
----------------------------------------------------------
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Residues in contact with CYS 17 (chain 2). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     132  ARG      3.1    19.1    +      -       -      +
     142  ARG      3.2     8.0    +      -       -      +
     162  LEU*     1.3    78.7    -      -       -      +
     182  SER*     1.3    56.1    +      -       -      +
     202  SER*     3.7     1.4    -      -       -      -
     212  ILE*     2.9    38.9    +      -       +      +
    1262  LEU*     4.1    14.6    -      -       -      -
    1762  LEU*     3.6    32.0    -      -       +      +
    1792  ILE*     3.9    17.3    -      -       -      -
    1802  SER*     3.7    29.6    -      -       -      -
----------------------------------------------------------
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Residues in contact with SER 18 (chain 2). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     142  ARG*     2.8    18.8    +      -       -      +
     152  ASP*     3.5    13.4    +      -       -      -
     162  LEU      3.2     0.2    -      -       -      -
     172  CYS*     1.3    75.8    -      -       -      +
     192  ARG*     1.3    66.5    +      -       -      +
     212  ILE*     3.8     9.3    -      -       -      +
     222  TRP*     3.0    23.7    +      -       -      +
----------------------------------------------------------
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Residues in contact with ARG 19 (chain 2). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     152  ASP      2.9    15.7    +      -       -      +
     162  LEU*     3.3    34.3    +      -       -      +
     182  SER*     1.3    76.1    -      -       -      +
     202  SER*     1.3    62.2    +      -       -      +
     222  TRP*     3.3     9.2    +      -       -      +
     232  LEU*     3.1    21.7    +      -       -      +
    1222  GLN*     3.7    40.1    +      -       -      +
    1252  GLU*     3.2    23.4    +      -       -      -
    1073  GLN*     3.3    23.5    -      -       -      +
----------------------------------------------------------
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Residues in contact with SER 20 (chain 2). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     162  LEU      3.0    15.3    +      -       -      -
     172  CYS      3.8     1.3    -      -       -      -
     192  ARG*     1.3    77.3    -      -       -      +
     212  ILE*     1.3    59.5    +      -       -      +
     232  LEU*     3.4     1.1    +      -       -      +
     242  ALA*     3.0    24.4    +      -       -      +
    1192  PHE*     3.5    16.8    -      -       -      -
    1222  GLN*     2.6    39.4    +      -       -      +
    1232  ILE*     4.7     4.1    -      -       -      +
    1262  LEU*     5.5     2.3    -      -       -      +
    1762  LEU*     3.5    27.4    -      -       -      +
----------------------------------------------------------
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Residues in contact with ILE 21 (chain 2). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     172  CYS*     2.9    30.0    +      -       +      +
     182  SER*     3.2     8.9    +      -       -      +
     202  SER*     1.3    74.3    -      -       -      +
     222  TRP*     1.3    66.6    +      -       -      +
     242  ALA*     3.3     5.6    +      -       -      +
     252  ARG*     3.1    54.1    +      -       -      +
    1732  ILE*     4.5    12.5    -      -       +      +
    1762  LEU*     3.7    32.1    -      -       +      +
    1772  ARG*     4.0    22.9    -      -       +      -
    1802  SER*     5.4     2.5    -      -       -      +
----------------------------------------------------------
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Residues in contact with TRP 22 (chain 2). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     182  SER      3.0    12.9    +      -       -      +
     192  ARG*     3.5    11.0    -      -       -      +
     212  ILE*     1.3    80.2    -      -       -      +
     232  LEU*     1.3   101.2    +      -       +      +
     252  ARG*     3.3     7.3    +      -       +      +
     262  LYS*     2.9    46.9    +      -       +      +
----------------------------------------------------------
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Residues in contact with LEU 23 (chain 2). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     192  ARG      3.1    11.5    +      -       -      +
     202  SER      3.7     7.4    -      -       -      +
     222  TRP*     1.3   102.2    -      -       +      +
     242  ALA*     1.3    63.0    +      -       -      +
     262  LYS*     3.0     8.2    +      -       +      +
     272  ILE*     3.0    29.9    +      -       +      +
    1152  GLN*     3.7    31.4    -      -       +      +
    1182  ALA*     3.8     8.5    -      -       +      -
    1192  PHE*     3.5    42.0    -      -       +      +
    1222  GLN*     3.7    20.2    -      -       -      +
----------------------------------------------------------
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Residues in contact with ALA 24 (chain 2). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     202  SER      3.0    17.6    +      -       -      +
     212  ILE*     3.6     5.4    -      -       -      +
     232  LEU*     1.3    76.7    -      -       -      +
     252  ARG*     1.3    61.4    +      -       -      +
     272  ILE*     3.3    10.5    +      -       -      +
     282  ARG      3.1    16.8    +      -       -      -
     802  TYR*     5.1     0.9    -      -       -      +
    1192  PHE*     4.1    17.6    -      -       +      -
    1692  THR*     3.5    23.0    -      -       +      +
    1722  SER*     4.5     6.5    -      -       -      -
    1732  ILE*     3.7    21.8    -      -       +      -
    1762  LEU*     5.2     0.4    -      -       +      -
----------------------------------------------------------
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Residues in contact with ARG 25 (chain 2). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     212  ILE*     3.1    36.7    +      -       -      +
     222  TRP*     3.8     6.3    -      -       +      +
     242  ALA*     1.3    75.6    -      -       -      +
     262  LYS*     1.3    57.1    +      -       -      +
     282  ARG*     3.0    15.0    +      -       +      +
     292  SER*     2.9    31.0    +      -       -      -
    1732  ILE*     3.4    41.4    -      -       +      +
    1772  ARG*     5.2     7.9    -      -       -      +
----------------------------------------------------------
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Residues in contact with LYS 26 (chain 2). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     222  TRP*     2.9    47.3    +      -       +      +
     232  LEU*     3.0    15.5    +      -       +      +
     252  ARG*     1.3    73.5    -      -       -      +
     272  ILE*     1.3    63.9    +      -       -      +
     292  SER*     3.5     8.6    +      -       -      -
     302  ASP*     2.9    50.2    +      -       -      +
    1152  GLN*     3.6    20.2    -      -       -      +
----------------------------------------------------------
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Residues in contact with ILE 27 (chain 2). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     232  LEU*     3.0    24.2    +      -       +      +
     242  ALA*     3.5     9.2    -      -       -      +
     252  ARG      3.2     0.2    -      -       -      -
     262  LYS*     1.3    74.0    -      -       -      +
     282  ARG*     1.3    66.9    +      -       -      +
     302  ASP*     3.3     2.5    +      -       -      +
     312  LEU*     2.9    39.7    +      -       +      +
     802  TYR*     4.5    15.5    -      -       +      -
    1122  LEU*     4.2     9.6    -      -       +      -
    1152  GLN*     3.8    42.6    -      -       +      +
    1162  VAL*     4.0    21.3    -      -       +      +
    1192  PHE*     4.8     2.7    -      -       +      -
    1652  LEU*     4.2     7.0    -      -       +      -
    1692  THR*     3.7    16.8    -      -       +      -
----------------------------------------------------------
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Residues in contact with ARG 28 (chain 2). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     242  ALA      3.1     9.4    +      -       -      +
     252  ARG*     3.0    17.5    +      -       -      +
     272  ILE*     1.3    78.8    -      -       -      +
     292  SER*     1.3    63.5    +      -       -      +
     312  LEU*     3.3     7.5    +      -       -      +
     322  THR*     3.2    27.0    +      -       -      +
    1662  SER*     4.9     9.0    +      -       -      +
    1692  THR*     3.6    25.1    -      -       -      +
    1702  VAL*     3.9    28.5    -      -       -      +
    1732  ILE*     5.0    13.5    -      -       -      +
----------------------------------------------------------
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Residues in contact with SER 29 (chain 2). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     252  ARG      2.9    13.3    +      -       -      -
     262  LYS*     3.6    16.5    -      -       -      -
     282  ARG*     1.3    74.9    -      -       -      +
     302  ASP*     1.3    68.5    +      -       -      +
     322  THR*     3.2    20.4    +      -       -      -
     332  ALA*     3.6     6.2    +      -       -      +
----------------------------------------------------------
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Residues in contact with ASP 30 (chain 2). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     262  LYS*     2.9    41.9    +      -       -      +
     272  ILE*     3.5    10.5    -      -       -      +
     292  SER*     1.3    80.6    -      -       -      +
     312  LEU*     1.3    59.5    +      -       -      +
     332  ALA*     3.1     9.1    +      -       -      +
     342  LEU*     2.9    30.2    +      -       +      +
    1112  THR*     4.7     7.4    -      -       -      +
    1122  LEU*     4.8     6.9    -      -       +      +
    1152  GLN*     3.0    29.5    +      -       -      +
----------------------------------------------------------
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Residues in contact with LEU 31 (chain 2). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     272  ILE*     2.9    29.8    +      -       +      +
     282  ARG*     3.3     4.7    +      -       -      +
     302  ASP*     1.3    72.8    -      -       -      +
     322  THR*     1.3    58.7    +      -       -      +
     342  LEU*     4.1     8.7    -      -       +      -
     352  THR*     2.6    40.2    +      -       -      +
    1122  LEU*     3.7    32.5    -      -       +      -
    1622  LEU*     3.8    22.7    -      -       +      +
    1652  LEU*     3.6    34.3    -      -       +      -
    1662  SER*     3.6    31.6    -      -       -      +
----------------------------------------------------------
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Residues in contact with THR 32 (chain 2). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     282  ARG*     3.2    16.6    +      -       -      +
     292  SER*     3.2    11.1    +      -       -      -
     312  LEU*     1.3    76.6    -      -       -      +
     332  ALA*     1.3    63.3    +      -       -      +
     352  THR*     4.0     2.3    -      -       -      -
     362  GLU*     3.0    41.3    +      -       -      +
    1662  SER*     5.4     0.2    +      -       -      -
----------------------------------------------------------
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Residues in contact with ALA 33 (chain 2). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     292  SER      3.6     5.9    +      -       -      +
     302  ASP*     3.1     8.8    +      -       -      +
     322  THR*     1.3    78.0    -      -       -      +
     342  LEU*     1.3    65.3    +      -       -      +
     362  GLU*     3.3     8.0    +      -       -      +
     372  SER*     3.1    26.4    +      -       -      -
----------------------------------------------------------
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Residues in contact with LEU 34 (chain 2). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     302  ASP*     2.9    18.4    +      -       +      +
     312  LEU*     4.0    12.6    -      -       +      +
     332  ALA*     1.3    76.7    -      -       -      +
     352  THR*     1.3    57.6    +      -       -      +
     372  SER*     3.2    10.9    +      -       -      -
     382  TYR*     2.8    29.0    +      -       +      +
    1052  PHE*     4.2    21.3    -      -       +      -
    1082  ALA*     3.7    33.0    -      -       +      +
    1092  ILE*     4.1    12.1    -      -       +      -
    1122  LEU*     4.1    29.4    -      -       +      -
    1622  LEU*     4.3    11.7    -      -       +      -
----------------------------------------------------------
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Residues in contact with THR 35 (chain 2). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     312  LEU*     2.6    33.9    +      -       -      +
     322  THR*     4.0     3.4    -      -       -      -
     342  LEU*     1.3    68.9    -      -       -      +
     362  GLU*     1.3    70.8    +      -       -      +
     382  TYR*     3.1     6.7    +      -       +      +
     392  VAL*     2.9    33.7    +      -       +      +
    1592  LEU*     3.7    28.7    -      -       +      -
    1622  LEU*     4.0    22.6    -      -       +      +
    1632  GLN*     5.0     7.7    -      -       +      +
    1662  SER*     5.0     2.4    +      -       -      -
----------------------------------------------------------
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Residues in contact with GLU 36 (chain 2). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     322  THR*     3.0    35.6    +      -       -      +
     332  ALA*     3.4    11.7    -      -       -      +
     352  THR*     1.3    78.4    -      -       -      +
     372  SER*     1.3    59.7    +      -       -      +
     392  VAL*     3.4     5.2    +      -       -      +
     402  LYS*     2.9    31.0    +      -       -      +
----------------------------------------------------------
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Residues in contact with SER 37 (chain 2). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     332  ALA      3.1    11.7    +      -       -      -
     342  LEU*     3.3    14.3    -      -       -      -
     362  GLU*     1.3    76.1    -      -       -      +
     382  TYR*     1.3    55.3    +      -       -      +
     402  LYS*     3.1     7.1    +      -       -      +
     412  HIS*     2.7    58.5    +      -       -      -
----------------------------------------------------------
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Residues in contact with TYR 38 (chain 2). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     342  LEU*     2.8    17.4    +      -       -      +
     352  THR*     3.5    11.7    -      -       -      +
     372  SER*     1.3    71.0    -      -       -      +
     392  VAL*     1.3    59.7    +      -       -      +
     412  HIS*     3.2     7.0    +      -       -      +
     422  GLN*     2.9    54.9    +      -       +      +
     442  LEU*     3.9    10.5    -      -       +      -
     902  LEU*     4.9     1.2    -      -       -      +
    1052  PHE*     3.3    48.2    -      +       +      -
    1542  LYS      3.2    15.1    +      -       -      -
    1552  LYS*     2.7    33.4    +      -       -      -
    1582  GLY*     3.2     9.0    -      -       -      -
    1592  LEU*     3.4    34.1    -      -       +      -
    1622  LEU*     4.4     9.0    -      -       +      -
----------------------------------------------------------
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Residues in contact with VAL 39 (chain 2). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     352  THR*     2.9    25.0    +      -       +      +
     362  GLU*     3.7     5.2    -      -       -      +
     382  TYR*     1.3    76.2    -      -       +      +
     402  LYS*     1.3    63.4    +      -       -      +
     432  GLY*     3.1    20.1    +      -       -      -
     442  LEU*     3.2    38.6    +      -       +      -
    1592  LEU*     3.7    34.3    -      -       +      -
----------------------------------------------------------
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Residues in contact with LYS 40 (chain 2). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     362  GLU      2.9    18.8    +      -       -      +
     372  SER*     3.6     5.6    -      -       -      +
     392  VAL*     1.3    77.6    -      -       -      +
     412  HIS*     1.3    87.8    +      -       -      +
     432  GLY*     3.9     6.4    +      -       -      -
----------------------------------------------------------
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Residues in contact with HIS 41 (chain 2). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     372  SER*     2.7    38.2    +      -       -      +
     382  TYR*     3.7     3.1    -      -       -      +
     402  LYS*     1.3   105.7    +      -       -      +
     422  GLN*     1.3    77.9    +      -       -      +
     432  GLY      3.5     0.2    -      -       -      -
    1052  PHE*     6.5     1.3    -      -       +      -
----------------------------------------------------------
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Residues in contact with GLN 42 (chain 2). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     382  TYR*     2.9    52.1    +      -       +      +
     412  HIS*     1.3    95.7    +      -       -      +
     432  GLY*     1.3    63.1    +      -       -      +
     442  LEU*     3.5    21.3    -      -       +      -
    1052  PHE*     6.3     0.6    -      -       -      -
    1552  LYS*     2.8    52.5    +      -       +      +
----------------------------------------------------------
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A short description of the analytical approach
The contact analysis used in this page is based upon the approach developed in: Sobolev V., Wade R.C., Vriend G. and Edelman M. PROTEINS (1996) 25, 120-129. Contact legitimacy depends on the hydrophobic-hydrophilic properties of the contacting atoms. In order to define it, for each inter-atomic contact, eight atom classes have been introduced:


   I  Hydrophilic      - N and O that can donate and accept hydrogen bonds
                         (e.g., oxygen of hydroxyl group of Ser. or Thr)
  II  Acceptor         - N or O that can only accept a hydrogen bond
 III  Donor            - N that can only donate a hydrogen bond
  IV  Hydrophobic      - Cl, Br, I and all C atoms that are not in
                         aromatic rings and do not have a covalent bond to
                         a N or O atom
   V  Aromatic         - C in aromatic rings irrespective of any other 
                         bonds formed by the atom
  VI  Neutral          - C atoms that have a covalent bond to at least one
                         atom of class I or two or more atoms from class II
                         or III; atoms; S, F, P, and metal atoms in all cases
 VII  Neutral-donor    - C atoms that have a covalent bond with only one
                         atom of class III
VIII  Neutral-acceptor - C atoms that have a covalent bond with only 
                         one atom of class II
For each pair of contacts the state of legitimacy is shown below:

Legend:
+, legitimate
-, illegitimate
------------------------------------------------------------
  Atomic class           I  II  III   IV   V   VI  VII  VIII
------------------------------------------------------------
   I  (Hydrophilic)      +   +    +    -   +   +    +    +
  II  (Acceptor)         +   -    +    -   +   +    +    -
 III  (Donor)            +   +    -    -   +   +    -    +
  IV  (Hydrophobic)      -   -    -    +   +   +    +    +
   V  (Aromatic)         +   +    +    +   +   +    +    +
  VI  (Neutral)          +   +    +    +   +   +    +    +
 VII  (Neutral-donor)    +   +    -    +   +   +    -    +
VIII  (Neutral-acceptor) +   -    +    +   +   +    +    -
------------------------------------------------------------
Warning!
Atom classes for heterogroups are automatically assigned based on the atomic coordinates. However, in three cases (see below) the automatic assignment is currently ambiguous. In these cases, the user is advised to manually analyse the full list of contacts using LPC software.
1. Carbon atoms belonging to a 4-, 5- or 6-member ring are 
   considered "aromatic" (Class V) if the ring is approximately
   planar, and "hydrophobic" (Class IV) or "neutral" (Classes
   VI, VII, VIII) if the ring is non-planar.
2. The oxygen atom of a carbonyl or hydroxy group is considered
   "hydroxy" (Class I) if the CO bond is longer than 1.29 Å, and
   "carbonyl" (Class II) if shorter.
3. All nitrogen atoms are considered "hydrophilic" (Class I).

Please E-mail any questions and/or suggestions concerning this page to Vladimir.Sobolev@weizmann.ac.il