Contacts of the helix formed by residues 22 - 51 (chain A) in PDB entry 3UON


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 GLU 22 (chain A).
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     20A  THR*     3.9    23.8    +      -       -      +
     21A  PHE*     1.3    97.2    -      -       +      +
     23A  VAL*     1.3    65.5    +      -       -      +
     24A  VAL*     3.3     5.4    -      -       -      -
     25A  PHE*     3.0    25.2    +      -       +      +
     26A  ILE*     3.7    17.3    +      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with VAL 23 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     20A  THR      3.3    30.7    -      -       -      +
     21A  PHE      3.2     3.7    -      -       -      +
     22A  GLU*     1.3    77.1    -      -       -      +
     24A  VAL*     1.3    64.4    +      -       -      +
     26A  ILE*     2.9    22.9    +      -       +      +
     27A  VAL*     3.0    28.2    +      -       +      +
     85A  VAL*     4.1    24.7    -      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with VAL 24 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     21A  PHE      4.7     6.2    +      -       -      +
     22A  GLU*     4.5     6.1    -      -       -      +
     23A  VAL*     1.3    80.7    -      -       -      +
     25A  PHE*     1.3    68.1    +      -       +      +
     27A  VAL*     3.8     7.3    -      -       +      +
     28A  LEU*     3.0    49.1    +      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with PHE 25 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     22A  GLU*     3.0    17.7    +      -       +      +
     23A  VAL      3.0     0.2    +      -       -      -
     24A  VAL*     1.3    81.3    -      -       +      +
     26A  ILE*     1.3    75.6    +      -       +      +
     28A  LEU*     3.2    12.3    +      -       +      +
     29A  VAL*     2.9    51.7    +      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ILE 26 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     20A  THR      6.2     1.8    -      -       -      +
     22A  GLU*     4.3    20.0    -      -       +      +
     23A  VAL*     2.9    13.5    +      -       +      +
     25A  PHE*     1.3    84.9    -      -       +      +
     27A  VAL*     1.3    61.9    +      -       +      +
     29A  VAL*     3.2     5.1    +      -       -      +
     30A  ALA*     2.9    32.4    +      -       +      +
     81A  THR*     4.7    16.4    -      -       +      -
     84A  THR*     6.1     0.9    -      -       -      +
     85A  VAL*     5.0    22.7    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with VAL 27 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     23A  VAL*     3.0    32.1    +      -       +      +
     24A  VAL*     3.8    10.3    -      -       +      +
     26A  ILE*     1.3    79.0    -      -       +      +
     28A  LEU*     1.3    61.2    +      -       +      +
     30A  ALA*     4.4     2.9    -      -       -      +
     31A  GLY*     2.8    28.3    +      -       -      +
     81A  THR*     5.4     8.3    -      -       +      -
     85A  VAL*     5.3     6.3    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with LEU 28 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     24A  VAL*     3.0    44.1    +      -       +      +
     25A  PHE*     3.5    10.3    -      -       +      +
     27A  VAL*     1.3    76.4    -      -       +      +
     29A  VAL*     1.3    56.0    +      -       +      +
     31A  GLY*     4.9     0.2    -      -       -      -
     32A  SER*     2.7    44.0    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with VAL 29 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     25A  PHE*     2.9    53.4    +      -       +      +
     26A  ILE*     3.7     4.9    -      -       -      +
     28A  LEU*     1.3    78.5    -      -       +      +
     30A  ALA*     1.3    59.9    +      -       -      +
     32A  SER*     3.5     5.2    -      -       -      -
     33A  LEU*     2.9    33.6    +      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ALA 30 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     26A  ILE*     2.9    22.1    +      -       +      +
     27A  VAL      4.4     1.1    -      -       -      +
     29A  VAL*     1.3    75.6    -      -       +      +
     31A  GLY*     1.3    57.4    +      -       -      +
     33A  LEU*     3.7     7.9    -      -       -      +
     34A  SER*     2.9    31.0    +      -       -      -
     77A  MET*     5.6     0.2    -      -       -      +
     78A  ASN*     4.8     1.6    -      -       -      +
     81A  THR*     3.4    36.6    -      -       +      +
    427A  TRP*     4.1    15.3    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with GLY 31 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     27A  VAL      2.8    21.4    +      -       -      -
     28A  LEU*     3.7     0.7    -      -       -      -
     30A  ALA*     1.3    74.1    -      -       -      +
     32A  SER*     1.3    59.3    +      -       -      +
     34A  SER*     3.3     6.7    +      -       -      -
     35A  LEU*     2.9    29.2    +      -       -      +
     78A  ASN*     5.2     3.4    -      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with SER 32 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     28A  LEU*     2.7    30.3    +      -       -      +
     29A  VAL*     3.5     5.4    -      -       -      -
     31A  GLY*     1.3    71.6    -      -       -      +
     33A  LEU*     1.3    60.0    +      -       -      +
     35A  LEU*     2.9    12.3    +      -       -      +
     36A  VAL*     2.8    37.0    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with LEU 33 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     29A  VAL*     2.9    20.2    +      -       +      +
     30A  ALA*     3.7     6.5    -      -       -      +
     32A  SER*     1.3    76.2    -      -       -      +
     34A  SER*     1.3    62.0    +      -       -      +
     36A  VAL*     3.4     8.6    +      -       +      +
     37A  THR*     2.9    28.1    +      -       -      -
     77A  MET*     4.0     9.0    -      -       +      -
    427A  TRP*     3.8    28.7    -      -       +      -
    431A  ILE*     3.6    28.7    -      -       +      -
    434A  THR*     4.0    23.1    -      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with SER 34 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     30A  ALA      2.9    18.5    +      -       -      -
     31A  GLY*     3.7     4.7    -      -       -      -
     33A  LEU*     1.3    76.5    -      -       -      +
     35A  LEU*     1.3    57.4    +      -       -      +
     37A  THR*     3.4     1.7    +      -       -      -
     38A  ILE*     3.1    35.5    +      -       -      +
     73A  GLY      2.3    30.2    +      -       -      -
     74A  VAL*     4.6     0.2    -      -       -      -
     77A  MET*     3.9    18.8    -      -       -      -
     78A  ASN*     3.1    24.9    +      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with LEU 35 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     31A  GLY      2.9    13.1    +      -       -      +
     32A  SER*     2.9    14.0    +      -       -      +
     34A  SER*     1.3    76.0    -      -       -      +
     36A  VAL*     1.3    67.3    +      -       +      +
     38A  ILE*     3.0    21.2    -      -       +      +
     39A  ILE*     3.0    43.4    +      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with VAL 36 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     32A  SER*     2.8    26.6    +      -       -      +
     33A  LEU*     3.7     9.6    -      -       +      +
     35A  LEU*     1.3    72.9    -      -       +      +
     37A  THR*     1.3    58.5    +      -       -      +
     39A  ILE*     3.6    10.5    -      -       +      +
     40A  GLY*     2.9    27.4    +      -       -      -
    434A  THR*     3.9    21.7    -      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with THR 37 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     33A  LEU      2.9    16.5    +      -       -      -
     34A  SER*     3.6     5.6    -      -       -      -
     35A  LEU      3.2     0.4    -      -       -      -
     36A  VAL*     1.3    77.6    -      -       -      +
     38A  ILE*     1.3    62.3    +      -       -      +
     40A  GLY*     3.3     0.7    +      -       -      -
     41A  ASN*     2.8    39.3    +      -       -      +
     69A  ASP      3.5    24.2    -      -       -      +
     73A  GLY*     3.8    16.4    -      -       -      +
     77A  MET*     3.7     7.2    -      -       -      +
    433A  SER*     3.8    15.0    -      -       -      +
    434A  THR*     2.5    31.9    +      -       -      +
    437A  PRO*     6.2     0.2    -      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with ILE 38 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     34A  SER*     3.1    22.2    +      -       -      +
     35A  LEU*     3.0    37.0    -      -       +      +
     37A  THR*     1.3    76.8    -      -       -      +
     39A  ILE*     1.3    61.2    +      -       +      +
     42A  ILE*     3.1    39.9    +      -       +      +
     70A  LEU*     3.4    23.1    -      -       +      +
     73A  GLY*     3.6     3.8    -      -       -      +
     74A  VAL*     3.6    35.0    -      -       +      +
     78A  ASN*     6.1     0.7    -      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ILE 39 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     35A  LEU*     3.0    40.9    +      -       +      +
     36A  VAL*     3.6    11.9    -      -       +      +
     38A  ILE*     1.3    79.8    -      -       +      +
     40A  GLY*     1.3    66.0    +      -       -      +
     42A  ILE*     4.3     6.4    -      -       +      +
     43A  LEU*     3.0    45.5    +      -       +      +
    455A  LEU*     5.7     3.4    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with GLY 40 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     36A  VAL*     2.9    20.5    +      -       -      -
     37A  THR      3.7     0.9    -      -       -      -
     38A  ILE      3.1     0.2    -      -       -      -
     39A  ILE*     1.3    84.2    -      -       -      +
     41A  ASN*     1.3    57.6    +      -       -      +
     43A  LEU*     3.2     9.1    -      -       -      +
     44A  VAL*     3.1    27.9    +      -       -      +
    437A  PRO*     3.8    19.0    -      -       -      +
    451A  PHE*     4.8     0.7    -      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with ASN 41 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     37A  THR*     2.8    32.3    +      -       -      +
     38A  ILE      4.3     0.2    -      -       -      +
     40A  GLY*     1.3    70.0    -      -       -      +
     42A  ILE*     1.3    61.3    -      -       -      +
     43A  LEU      3.0     1.1    -      -       -      -
     44A  VAL*     3.0     7.6    +      -       -      +
     45A  MET*     2.8    33.2    +      -       -      +
     66A  ALA*     3.3    34.4    -      -       -      +
     69A  ASP*     3.2    26.7    -      -       -      +
     70A  LEU*     4.0    10.1    -      -       +      -
    433A  SER      3.3    21.4    +      -       -      +
    436A  ASN*     5.0     0.5    -      -       -      +
    437A  PRO*     3.8    16.3    -      -       -      +
    440A  TYR*     5.5     1.2    -      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with ILE 42 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     38A  ILE*     3.1    27.4    +      -       +      +
     39A  ILE*     4.3     5.2    -      -       -      +
     41A  ASN*     1.3    76.6    -      -       -      +
     43A  LEU*     1.3    58.7    +      -       +      +
     45A  MET*     3.9     9.1    -      -       +      +
     46A  VAL*     2.9    41.1    +      -       +      +
     70A  LEU*     3.5    29.2    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with LEU 43 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     39A  ILE*     3.0    35.0    +      -       +      +
     40A  GLY*     3.2     9.6    -      -       -      +
     41A  ASN      3.0     0.6    -      -       -      -
     42A  ILE*     1.3    81.1    -      -       +      +
     44A  VAL*     1.3    52.6    +      -       -      +
     46A  VAL*     4.6     3.1    -      -       +      -
     47A  SER*     2.7    37.4    +      -       -      -
    451A  PHE*     3.5    32.1    -      -       +      -
    454A  LEU*     3.7    20.4    -      -       +      +
    455A  LEU*     3.8    31.6    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with VAL 44 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     40A  GLY      3.1    15.6    +      -       -      +
     41A  ASN*     3.0     9.7    +      -       -      +
     43A  LEU*     1.3    73.9    -      -       -      +
     45A  MET*     1.3    66.8    +      -       -      +
     47A  SER*     3.1     3.0    +      -       -      -
     48A  ILE*     3.0    31.7    +      -       +      +
     62A  LEU*     4.6     2.2    -      -       +      +
     63A  PHE*     5.5     0.2    -      -       -      -
     66A  ALA*     4.2    13.0    -      -       +      -
    437A  PRO*     3.7    12.8    -      -       +      -
    440A  TYR*     3.7    35.9    -      -       +      -
    447A  PHE*     4.2    15.3    -      -       +      -
    451A  PHE*     3.4    25.8    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with MET 45 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     41A  ASN      2.8    22.8    +      -       -      +
     42A  ILE*     3.9     7.2    -      -       +      +
     44A  VAL*     1.3    73.0    -      -       -      +
     46A  VAL*     1.3    62.6    +      -       +      +
     48A  ILE*     3.5     0.5    +      -       -      +
     49A  LYS*     3.1    24.4    +      -       -      +
     63A  PHE*     3.4    40.1    -      -       +      +
     66A  ALA*     3.7    16.6    -      -       +      +
     67A  CYS*     3.7    34.3    -      -       -      -
     70A  LEU*     4.1    27.1    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with VAL 46 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     42A  ILE*     2.9    34.2    +      -       +      +
     43A  LEU*     4.0     5.8    -      -       +      +
     45A  MET*     1.3    75.1    -      -       +      +
     47A  SER*     1.3    61.4    +      -       -      +
     49A  LYS*     3.1     6.6    +      -       -      +
     50A  VAL*     2.8    41.8    +      -       +      +
    454A  LEU*     3.6    28.9    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with SER 47 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     43A  LEU      2.7    25.3    +      -       -      -
     44A  VAL      3.4     5.2    -      -       -      -
     46A  VAL*     1.3    75.7    -      -       -      +
     48A  ILE*     1.3    59.1    +      -       -      +
     50A  VAL*     4.1     1.1    -      -       -      -
     51A  ASN*     3.2    30.7    +      -       -      +
     54A  LEU*     3.3     4.9    -      -       -      +
    447A  PHE*     4.1     9.6    -      -       -      -
    450A  THR*     3.3    20.4    -      -       -      +
    451A  PHE*     2.9    28.8    -      -       -      -
    454A  LEU*     3.0    13.5    -      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ILE 48 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     44A  VAL*     3.0    20.8    +      -       +      +
     45A  MET      3.8     3.4    -      -       -      +
     47A  SER*     1.3    75.7    -      -       -      +
     49A  LYS*     1.3    67.3    +      -       +      +
     51A  ASN      3.3     4.9    -      -       -      +
     54A  LEU*     3.9    20.6    -      -       -      +
     55A  GLN*     3.3    28.4    -      -       +      +
     59A  ASN*     3.0    37.9    -      -       +      +
     60A  TYR*     5.0     9.6    -      -       +      -
     62A  LEU*     4.7     1.1    -      -       +      -
     63A  PHE*     4.2    26.7    -      -       +      +
    447A  PHE*     3.4    30.1    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with LYS 49 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     45A  MET      3.1    13.4    +      -       -      +
     46A  VAL*     3.1     8.0    +      -       +      +
     48A  ILE*     1.3    79.1    -      -       +      +
     50A  VAL*     1.3    58.6    +      -       +      +
     55A  GLN*     3.4    16.5    +      -       -      +
     63A  PHE*     3.9    29.6    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with VAL 50 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     46A  VAL*     2.8    36.9    +      -       +      +
     47A  SER*     3.9     8.7    -      -       -      +
     49A  LYS*     1.3    78.4    -      -       +      +
     51A  ASN*     1.3    63.9    +      -       +      +
     52A  ARG      4.1     1.3    +      -       -      -
     55A  GLN*     4.8     0.4    -      -       -      -
    450A  THR*     4.6     3.8    -      -       +      -
    454A  LEU*     4.2    15.3    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with ASN 51 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     47A  SER      3.2    18.4    +      -       -      +
     48A  ILE      3.3     4.0    -      -       -      +
     49A  LYS      3.5     0.8    -      -       -      -
     50A  VAL*     1.3    79.6    -      -       +      +
     52A  ARG*     1.3    67.7    +      -       -      +
     53A  HIS*     3.1    24.3    +      -       -      +
     54A  LEU*     3.0    25.5    +      -       +      +
     55A  GLN*     3.2    13.9    +      -       -      +
    446A  THR*     3.7    12.1    -      -       -      +
    449A  LYS*     4.8    10.1    +      -       -      +
    450A  THR*     3.3    27.6    +      -       +      +
----------------------------------------------------------
 Back to top of page


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