Contacts of the helix formed by residues 252 - 278 (chain N) in PDB entry 5A31


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 LEU 252 (chain N).
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    151N  GLU*     6.1     1.1    -      -       -      +
    154N  HIS*     5.0    19.3    -      -       +      +
    158N  ARG*     3.6    30.7    -      -       -      +
    162N  PHE*     6.1     0.5    -      -       -      -
    247N  LEU*     3.0     8.6    +      -       -      -
    248N  HIS*     4.0    22.2    -      -       -      +
    249N  ARG      5.3     0.4    -      -       -      -
    250N  LEU*     3.8    10.1    -      -       -      +
    251N  SER*     1.3    90.2    -      -       -      +
    253N  LEU*     1.3    64.9    +      -       -      +
    254N  ALA*     4.2    12.8    -      -       +      +
    255N  ARG*     3.6    11.9    +      -       -      +
    256N  VAL*     4.0    12.6    +      -       -      +
----------------------------------------------------------
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Residues in contact with LEU 253 (chain N). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    177N  TYR*     5.3     1.1    -      -       -      +
    244N  SER*     3.9    20.4    -      -       -      +
    247N  LEU*     3.4    34.2    +      -       +      -
    248N  HIS*     3.9    19.5    -      -       +      +
    252N  LEU*     1.3    73.3    -      -       -      +
    254N  ALA*     1.3    65.3    +      -       +      +
    256N  VAL*     4.6     0.7    -      -       -      -
    257N  SER*     2.2    55.5    +      -       -      +
    258N  ALA      3.6     0.2    +      -       -      -
    303N  VAL*     3.9    30.7    -      -       +      +
    304N  PHE*     3.5    41.3    -      -       +      +
----------------------------------------------------------
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Residues in contact with ALA 254 (chain N). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
   1727A  ALA*     6.2     2.0    -      -       +      -
   1728A  SER*     3.6    25.4    +      -       -      -
    158N  ARG*     5.0     1.6    -      -       -      +
    252N  LEU*     3.1    16.5    -      -       +      +
    253N  LEU*     1.3    85.6    -      -       -      +
    255N  ARG*     1.3    60.4    +      -       -      +
    258N  ALA*     3.2    25.2    -      -       +      +
    304N  PHE*     5.2     5.6    -      -       +      -
----------------------------------------------------------
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Residues in contact with ARG 255 (chain N). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
   1728A  SER*     3.9    17.5    +      -       -      -
   1729A  GLU      3.4    23.2    +      -       -      -
   1730A  ALA*     4.0     5.7    -      -       -      +
   1731A  ARG*     3.8    27.7    -      -       -      +
    158N  ARG*     4.4    38.8    -      -       +      +
    162N  PHE*     4.1    42.0    +      -       +      +
    163N  PHE*     4.5    12.7    -      -       -      -
    252N  LEU*     3.6    11.7    +      -       +      +
    253N  LEU      3.2     1.0    -      -       -      -
    254N  ALA*     1.3    80.0    -      -       -      +
    256N  VAL*     1.3    71.5    +      -       +      +
    258N  ALA      3.9     1.2    +      -       -      -
    259N  GLU*     3.9    33.0    +      -       -      +
----------------------------------------------------------
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Residues in contact with VAL 256 (chain N). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    162N  PHE*     3.7    36.8    -      -       +      -
    169N  PHE*     3.8    26.7    -      -       +      -
    170N  GLN*     4.5     4.0    -      -       -      +
    173N  ILE*     3.9    16.7    -      -       +      +
    247N  LEU*     4.1    25.8    -      -       +      -
    251N  SER*     5.9     2.0    -      -       -      -
    252N  LEU      4.0    14.1    -      -       -      +
    253N  LEU      4.4     0.2    -      -       -      +
    255N  ARG*     1.3    82.2    -      -       +      +
    257N  SER*     1.3    67.8    +      -       -      +
    259N  GLU*     3.7     5.9    +      -       -      +
    260N  ALA*     3.5    18.5    +      -       -      +
----------------------------------------------------------
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Residues in contact with SER 257 (chain N). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    173N  ILE*     4.2     7.4    -      -       -      -
    177N  TYR*     3.5    33.7    -      -       -      -
    247N  LEU*     4.5     5.2    -      -       -      -
    253N  LEU*     2.2    53.5    +      -       -      +
    256N  VAL*     1.3    80.7    -      -       -      +
    258N  ALA*     1.3    51.0    +      -       -      +
    260N  ALA*     3.2     4.3    +      -       -      +
    261N  VAL*     2.7    40.6    +      -       -      +
    304N  PHE*     5.9     0.2    -      -       -      -
----------------------------------------------------------
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Residues in contact with ALA 258 (chain N). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
   1728A  SER*     5.2     3.1    -      -       -      +
    253N  LEU      3.6     1.6    +      -       -      -
    254N  ALA*     3.2    24.8    +      -       -      +
    255N  ARG      4.6     0.4    -      -       -      +
    256N  VAL      3.4     0.8    -      -       -      -
    257N  SER*     1.3    80.6    +      -       -      +
    259N  GLU*     1.3    62.5    +      -       +      +
    261N  VAL*     3.4    11.8    -      -       +      +
    262N  THR*     3.1    28.5    +      -       -      +
    304N  PHE*     5.0    11.9    -      -       +      -
----------------------------------------------------------
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Residues in contact with GLU 259 (chain N). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
   1730A  ALA*     3.1    39.4    -      -       +      +
   1731A  ARG*     3.7     7.3    +      -       -      +
   1732A  ALA*     5.4     8.4    -      -       +      +
    170N  GLN*     3.9    27.6    +      -       -      +
    255N  ARG*     3.9    30.2    +      -       -      +
    256N  VAL*     3.7     7.4    +      -       -      +
    257N  SER      3.3     0.4    -      -       -      -
    258N  ALA*     1.3    75.9    -      -       +      +
    260N  ALA*     1.3    66.1    -      -       -      +
    262N  THR*     3.5     7.2    -      -       -      +
    263N  THR*     3.2    27.8    +      -       -      +
----------------------------------------------------------
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Residues in contact with ALA 260 (chain N). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    170N  GLN*     4.0     5.9    +      -       -      +
    173N  ILE*     3.9    43.3    -      -       +      +
    174N  GLN*     4.1     6.7    -      -       -      +
    177N  TYR*     4.8     4.5    -      -       +      -
    256N  VAL      3.5    11.3    +      -       -      +
    257N  SER*     3.2     8.4    +      -       -      +
    259N  GLU*     1.3    79.4    -      -       -      +
    261N  VAL*     1.3    59.3    +      -       -      +
    263N  THR*     2.9    10.1    +      -       -      -
    264N  THR*     2.9    31.9    +      -       -      +
----------------------------------------------------------
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Residues in contact with VAL 261 (chain N). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    177N  TYR*     3.3    38.4    -      -       +      -
    181N  LEU*     5.9     0.2    -      -       -      +
    257N  SER*     2.7    31.4    +      -       -      +
    258N  ALA*     3.4    17.5    -      -       +      +
    259N  GLU      3.3     0.2    -      -       -      -
    260N  ALA*     1.3    72.0    -      -       -      +
    262N  THR*     1.3    65.0    +      -       -      +
    264N  THR*     2.7    21.5    +      -       -      +
    265N  LEU*     2.8    20.3    +      -       -      +
    299N  TRP*     5.2    12.0    +      -       +      +
    300N  LEU*     4.9    11.2    -      -       +      -
    303N  VAL*     4.9     9.4    -      -       +      -
    304N  PHE*     4.4    15.5    -      -       +      -
----------------------------------------------------------
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Residues in contact with THR 262 (chain N). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    258N  ALA      3.1    18.6    +      -       -      +
    259N  GLU*     3.5    10.3    -      -       -      +
    261N  VAL*     1.3    82.3    -      -       -      +
    263N  THR*     1.3    71.4    +      -       +      +
    265N  LEU*     3.5     4.2    +      -       -      +
    266N  HIS*     2.9    49.5    +      -       +      -
    327N  HIS*     4.7     9.2    +      -       -      -
----------------------------------------------------------
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Residues in contact with THR 263 (chain N). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    170N  GLN*     6.2     1.6    -      -       -      +
    174N  GLN*     4.0    17.0    -      -       +      +
    259N  GLU*     3.2    17.5    -      -       +      +
    260N  ALA*     2.9    10.7    +      -       -      -
    262N  THR*     1.3    83.7    -      -       +      +
    264N  THR*     1.3    69.6    +      -       -      +
    266N  HIS*     3.4     9.5    +      -       -      +
    267N  GLN*     3.2    29.2    +      -       -      +
----------------------------------------------------------
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Residues in contact with THR 264 (chain N). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    174N  GLN*     3.1    38.6    -      -       +      +
    177N  TYR*     4.2     7.3    -      -       +      +
    178N  GLY*     3.9    18.6    +      -       -      +
    181N  LEU*     5.4     4.7    -      -       -      +
    260N  ALA      2.9    15.1    +      -       -      +
    261N  VAL*     2.7    26.3    +      -       -      +
    263N  THR*     1.3    82.4    +      -       -      +
    265N  LEU*     1.3    59.0    +      -       -      +
    267N  GLN*     3.3    15.3    -      -       -      +
    268N  VAL*     2.8    36.9    +      -       -      +
    299N  TRP*     5.9     1.2    -      -       -      -
----------------------------------------------------------
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Residues in contact with LEU 265 (chain N). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    181N  LEU*     4.7    12.3    -      -       +      -
    261N  VAL      2.8    21.9    +      -       -      +
    262N  THR*     3.9     4.5    -      -       -      +
    264N  THR*     1.3    72.5    +      -       -      +
    266N  HIS*     1.3    75.9    +      -       +      +
    268N  VAL*     3.8     4.5    -      -       -      +
    269N  THR*     2.3    45.8    +      -       -      +
    296N  VAL*     3.9    26.0    -      -       +      -
    299N  TRP*     5.0     3.6    -      -       +      +
    300N  LEU*     4.1    25.8    -      -       +      -
    327N  HIS*     5.8     1.8    -      -       +      -
    328N  VAL*     3.9    29.2    -      -       +      -
    331N  PHE*     4.1     7.9    -      -       +      -
----------------------------------------------------------
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Residues in contact with HIS 266 (chain N). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    262N  THR*     2.9    40.0    +      -       +      -
    263N  THR*     3.6     9.2    -      -       -      +
    265N  LEU*     1.3    86.1    -      -       +      +
    267N  GLN*     1.3    63.3    +      -       -      +
    269N  THR*     3.3     3.3    +      -       -      -
    270N  ARG*     3.1    24.8    +      -       -      +
    327N  HIS*     4.0    18.2    -      +       -      -
    331N  PHE*     3.2    52.4    -      +       +      -
----------------------------------------------------------
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Residues in contact with GLN 267 (chain N). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    174N  GLN*     5.1     7.1    +      -       -      +
    263N  THR*     3.2    14.5    +      -       -      +
    264N  THR*     3.3    33.0    -      -       -      +
    266N  HIS*     1.3    79.4    -      -       -      +
    268N  VAL*     1.3    64.9    +      -       +      +
    270N  ARG*     3.0    16.8    +      -       -      +
    271N  GLU*     2.9    32.2    +      -       +      +
----------------------------------------------------------
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Residues in contact with VAL 268 (chain N). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    178N  GLY*     4.3    25.1    -      -       -      +
    181N  LEU*     4.2    23.6    -      -       +      -
    182N  ARG*     5.0     9.0    -      -       +      -
    185N  MET*     6.3     0.2    -      -       +      -
    264N  THR*     2.8    24.0    +      -       -      +
    265N  LEU*     3.8     4.9    -      -       -      +
    267N  GLN*     1.3    82.6    -      -       +      +
    269N  THR*     1.3    62.9    +      -       -      +
    271N  GLU*     3.0    39.6    +      -       -      +
    272N  ARG*     3.1    16.4    +      -       +      +
    292N  TRP*     4.7    14.4    -      -       +      -
----------------------------------------------------------
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Residues in contact with THR 269 (chain N). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    265N  LEU*     2.3    40.7    +      -       +      +
    266N  HIS      3.5     4.7    -      -       -      -
    268N  VAL*     1.3    75.1    -      -       -      +
    270N  ARG*     1.3    58.9    +      -       -      +
    272N  ARG*     3.5     2.1    +      -       -      +
    273N  MET*     3.0    30.7    +      -       +      +
    289N  PHE*     5.1     2.1    -      -       +      -
    292N  TRP*     3.4    38.1    -      -       +      -
    328N  VAL*     5.6     2.9    -      -       +      -
    331N  PHE*     4.1    17.3    -      -       +      -
    332N  PHE*     4.4    22.2    -      -       +      -
    335N  ILE*     4.8     5.6    -      -       +      -
----------------------------------------------------------
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Residues in contact with ARG 270 (chain N). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    266N  HIS*     3.1    19.1    +      -       -      +
    267N  GLN*     3.0    17.5    +      -       -      +
    269N  THR*     1.3    73.1    -      -       -      +
    271N  GLU*     1.3    59.8    +      -       -      +
    273N  MET*     3.3     6.0    +      -       +      +
    274N  GLU*     2.8    44.3    +      -       +      +
    331N  PHE*     4.6     7.7    -      -       -      -
    335N  ILE*     3.7    46.4    -      -       +      +
    339N  LEU*     6.0     4.3    -      -       +      -
----------------------------------------------------------
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Residues in contact with GLU 271 (chain N). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    182N  ARG*     4.4    19.1    +      -       -      +
    267N  GLN*     2.9    26.0    +      -       +      +
    268N  VAL*     3.0    40.6    -      -       -      +
    270N  ARG*     1.3    74.9    -      -       -      +
    272N  ARG*     1.3    63.3    +      -       -      +
    274N  GLU*     3.4     5.4    +      -       -      +
    275N  ASP*     3.3    26.1    +      -       -      +
----------------------------------------------------------
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Residues in contact with ARG 272 (chain N). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    189N  ARG*     5.4    17.7    -      -       -      +
    212N  TYR*     4.6     4.8    +      -       -      -
    268N  VAL*     3.1    17.4    +      -       +      +
    269N  THR      3.7     4.7    -      -       -      +
    271N  GLU*     1.3    75.0    +      -       -      +
    273N  MET*     1.3    69.2    +      -       -      +
    275N  ASP*     3.3    33.3    +      -       -      +
    276N  ARG*     3.4    44.4    -      -       -      +
    288N  GLU*     4.5    10.9    +      -       -      -
    289N  PHE*     4.2    13.9    -      -       +      -
    292N  TRP*     3.4    49.3    -      -       +      +
----------------------------------------------------------
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Residues in contact with MET 273 (chain N). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    269N  THR*     3.0    16.0    +      -       +      +
    270N  ARG*     3.6     4.7    -      -       +      +
    272N  ARG*     1.3    82.0    -      -       -      +
    274N  GLU*     1.3    54.4    +      -       -      +
    277N  CYS*     2.6    61.1    +      -       -      +
    289N  PHE*     3.9    14.1    -      -       +      -
    332N  PHE*     3.1    44.4    -      -       +      +
    335N  ILE*     3.3    35.2    -      -       +      -
    336N  TYR*     3.4    33.7    -      -       +      +
    339N  LEU*     3.8    11.4    -      -       +      -
----------------------------------------------------------
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Residues in contact with GLU 274 (chain N). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    270N  ARG*     2.8    32.3    +      -       +      +
    271N  GLU*     3.7     7.6    -      -       -      +
    272N  ARG      3.3     0.4    -      -       -      -
    273N  MET*     1.3    74.1    -      -       -      +
    275N  ASP*     1.3    64.2    +      -       -      +
    276N  ARG      3.4     0.3    +      -       -      -
    277N  CYS*     3.8     5.2    +      -       -      -
    278N  ARG*     2.3    62.0    +      -       -      +
    339N  LEU*     4.1    19.8    -      -       +      +
----------------------------------------------------------
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Residues in contact with ASP 275 (chain N). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    212N  TYR*     4.9     6.9    +      -       -      -
    271N  GLU      3.3    11.5    +      -       -      +
    272N  ARG*     3.3    24.8    +      -       -      +
    274N  GLU*     1.3    81.1    -      -       -      +
    276N  ARG*     1.3    96.5    +      -       -      +
    278N  ARG*     5.1     5.5    -      -       -      +
----------------------------------------------------------
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Residues in contact with ARG 276 (chain N). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    208N  ALA*     5.0    10.7    -      -       -      +
    212N  TYR*     3.2    26.1    +      -       -      -
    272N  ARG*     3.4    40.4    -      -       -      +
    273N  MET      3.9     1.3    -      -       -      +
    275N  ASP*     1.3    88.3    +      -       -      +
    277N  CYS*     1.3    75.0    +      -       -      +
    278N  ARG      3.1    10.7    +      -       -      +
    279N  GLY*     3.6     1.6    +      -       -      -
    283N  ARG*     4.2    13.3    -      -       -      +
    285N  PHE*     3.2    30.0    -      -       +      -
    288N  GLU*     2.8    40.3    +      -       -      -
    289N  PHE*     4.8    11.9    -      -       +      -
----------------------------------------------------------
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Residues in contact with CYS 277 (chain N). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    273N  MET*     2.6    59.8    +      -       -      +
    274N  GLU*     3.8     3.8    +      -       -      +
    276N  ARG*     1.3    72.3    -      -       -      +
    278N  ARG*     1.3    53.4    +      -       +      +
    279N  GLY      2.7    18.5    +      -       -      -
    280N  GLU      4.5     0.7    +      -       -      -
    285N  PHE*     3.2    19.6    -      -       -      -
    289N  PHE*     5.1     4.5    -      -       -      -
    336N  TYR*     4.1    23.6    -      -       -      -
    339N  LEU*     3.8    20.4    -      -       +      -
    340N  ARG*     3.3    18.0    +      -       -      +
    343N  GLU*     4.0     1.7    -      -       -      +
----------------------------------------------------------
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Residues in contact with ARG 278 (chain N). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    274N  GLU*     2.3    50.3    +      -       -      +
    275N  ASP      5.1     5.2    -      -       -      +
    276N  ARG      3.1     7.9    +      -       -      +
    277N  CYS*     1.3    69.8    -      -       -      +
    279N  GLY*     1.3    59.9    +      -       -      +
    339N  LEU*     4.8    16.2    +      -       -      +
    342N  GLU*     5.9     4.0    -      -       -      +
    343N  GLU*     2.8    43.6    +      -       -      +
----------------------------------------------------------
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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