Contacts of the helix formed by residues 49 - 73 (chain A) in PDB entry 3N3B


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 THR 49 (chain A).
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     47A  THR      3.8     3.1    +      -       -      +
     48A  LEU*     1.3    76.8    -      -       -      +
     50A  VAL*     1.3    60.3    +      -       -      +
     51A  VAL*     3.9    10.6    +      -       -      +
     52A  GLU*     3.0    37.8    +      -       -      +
     53A  GLN*     2.9    28.9    +      -       -      +
----------------------------------------------------------
 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
----------------------------------------------------------
     49A  THR*     1.3    73.1    -      -       -      +
     51A  VAL*     1.3    59.4    +      -       +      +
     53A  GLN*     3.4    17.2    +      -       -      +
     54A  GLN*     2.9    40.7    +      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with VAL 51 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     49A  THR*     3.9     9.2    +      -       -      +
     50A  VAL*     1.3    79.5    -      -       +      +
     52A  GLU*     1.3    58.7    +      -       +      +
     54A  GLN*     3.4     7.0    +      -       -      +
     55A  LEU*     2.9    29.5    +      -       +      +
    243A  GLU*     3.5    56.5    -      -       +      +
    244A  THR*     4.0    15.5    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with GLU 52 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     47A  THR      4.9     0.5    -      -       -      +
     48A  LEU*     3.6    27.7    -      -       +      +
     49A  THR*     3.0    41.6    +      -       -      +
     51A  VAL*     1.3    81.2    -      -       +      +
     53A  GLN*     1.3    53.1    +      -       -      +
     55A  LEU*     3.5     8.1    +      -       -      +
     56A  THR*     2.6    37.1    +      -       -      -
    171A  TYR*     5.2     1.4    -      -       -      -
    172A  PHE*     3.8    17.3    -      -       +      -
    177A  LYS*     5.3     5.8    -      -       -      +
    244A  THR*     5.6     0.2    -      -       +      -
    246A  TRP*     3.7    33.2    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with GLN 53 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     45A  TRP*     3.0    62.9    +      -       +      +
     46A  GLN*     4.8     2.4    -      -       -      +
     48A  LEU*     4.0    20.1    +      -       +      +
     49A  THR      2.9    15.3    +      -       -      +
     50A  VAL*     3.7    23.5    -      -       -      +
     52A  GLU*     1.3    74.7    -      -       -      +
     54A  GLN*     1.3    64.7    -      -       -      +
     56A  THR*     3.3     4.2    +      -       -      -
     57A  MET*     3.1    34.4    +      -       +      +
    117A  ASP*     5.8     1.8    +      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with GLN 54 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     50A  VAL*     2.9    27.3    +      -       +      +
     51A  VAL*     3.7     7.8    -      -       -      +
     53A  GLN*     1.3    76.0    -      -       -      +
     55A  LEU*     1.3    61.9    +      -       -      +
     57A  MET*     3.5    12.5    +      -       +      +
     58A  ARG*     3.1    74.6    +      -       +      +
    121A  ALA*     5.3     0.2    -      -       -      +
    243A  GLU*     4.0    15.1    -      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with LEU 55 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     51A  VAL*     2.9    19.0    +      -       +      +
     52A  GLU*     3.7     7.6    -      -       -      +
     53A  GLN      3.3     0.2    -      -       -      -
     54A  GLN*     1.3    74.9    -      -       -      +
     56A  THR*     1.3    63.8    +      -       -      +
     58A  ARG*     3.5     6.2    +      -       -      +
     59A  VAL*     3.0    38.7    +      -       +      +
    168A  LEU*     3.8    17.7    -      -       +      -
    240A  LEU*     3.3    37.2    -      -       +      +
    241A  TYR*     3.7    31.2    -      -       +      -
    244A  THR*     3.9    12.6    -      -       +      -
    246A  TRP*     3.8    25.1    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with THR 56 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     45A  TRP*     3.7    25.5    -      -       +      -
     48A  LEU*     4.7     0.7    -      -       -      +
     52A  GLU      2.6    24.6    +      -       -      -
     53A  GLN      3.5     6.1    -      -       -      -
     55A  LEU*     1.3    76.1    -      -       -      +
     57A  MET*     1.3    62.0    +      -       +      +
     59A  VAL*     3.4     3.1    +      -       -      +
     60A  PHE*     3.2    53.4    +      -       +      -
    108A  ILE*     5.6     3.4    -      -       +      -
    112A  LEU*     6.4     0.7    -      -       +      -
    113A  CYS*     6.0     0.9    -      -       -      -
    168A  LEU*     3.6    11.7    -      -       +      +
    172A  PHE*     3.6    20.1    -      -       +      -
    178A  LEU*     4.9     8.7    -      -       +      -
    181A  THR*     6.1     0.4    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with MET 57 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     45A  TRP*     4.3    12.1    -      -       +      -
     53A  GLN*     3.1    32.3    +      -       +      +
     54A  GLN*     4.1     9.0    -      -       +      +
     56A  THR*     1.3    80.4    -      -       +      +
     58A  ARG*     1.3    56.5    +      -       -      +
     60A  PHE      3.5     0.3    +      -       -      -
     61A  THR*     3.0    35.5    +      -       -      +
    109A  PHE*     3.9    16.8    -      -       +      -
    113A  CYS*     3.8    26.9    -      -       -      -
    114A  GLN      6.0     0.2    -      -       -      +
    117A  ASP*     3.7    47.1    -      -       +      +
    118A  VAL*     3.8    13.7    -      -       +      -
    121A  ALA*     3.7    15.0    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with ARG 58 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     54A  GLN*     3.1    60.6    +      -       +      +
     55A  LEU*     3.9     6.3    -      -       -      +
     57A  MET*     1.3    74.3    -      -       -      +
     59A  VAL*     1.3    64.9    +      -       -      +
     61A  THR*     3.1    16.2    +      -       -      -
     62A  GLY*     3.3     9.4    +      -       -      -
    121A  ALA*     4.3    12.9    -      -       +      +
    124A  TRP*     3.3    67.6    -      -       +      +
    125A  SER*     3.8     4.5    +      -       -      -
    236A  TYR*     4.4     2.6    +      -       -      -
    239A  GLU      5.1     4.2    +      -       -      -
    240A  LEU*     3.9    26.2    +      -       +      +
    243A  GLU*     5.3     2.8    +      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with VAL 59 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     55A  LEU*     3.0    33.0    +      -       +      +
     56A  THR      3.5     5.6    -      -       -      +
     57A  MET      3.3     0.2    -      -       -      -
     58A  ARG*     1.3    77.8    -      -       -      +
     60A  PHE*     1.3    69.1    +      -       +      +
     62A  GLY*     3.3     3.3    +      -       -      -
     63A  LEU*     3.1    35.2    +      -       +      +
    165A  GLY*     3.4    36.1    -      -       -      +
    168A  LEU*     3.9    18.4    -      -       +      -
    236A  TYR*     4.9     2.5    +      -       -      -
    240A  LEU*     4.5    14.8    -      -       +      -
    241A  TYR*     4.2    12.8    -      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with PHE 60 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     56A  THR*     3.2    42.5    +      -       +      +
     59A  VAL*     1.3    81.9    -      -       +      +
     61A  THR*     1.3    55.1    +      -       -      +
     63A  LEU*     3.8    15.3    -      -       +      +
     64A  THR*     2.5    39.0    +      -       -      -
    105A  TYR*     3.6    27.9    -      +       +      -
    108A  ILE*     4.3    22.2    -      -       +      -
    109A  PHE*     3.5    22.4    -      +       +      -
    168A  LEU*     5.9     0.9    -      -       +      -
    169A  PRO*     4.4    18.2    -      -       +      -
    181A  THR*     4.2    18.4    -      -       +      -
    185A  ILE*     3.6    33.7    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with THR 61 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     57A  MET      3.0    22.0    +      -       -      +
     58A  ARG*     3.1     7.6    +      -       -      -
     60A  PHE*     1.3    76.2    -      -       -      +
     62A  GLY*     1.3    60.4    +      -       -      +
     64A  THR*     3.6     8.8    +      -       -      -
     65A  LEU*     3.4    19.4    +      -       -      +
    109A  PHE*     3.7    15.9    -      -       +      -
    118A  VAL      4.3     0.7    -      -       -      +
    121A  ALA*     3.3    14.6    +      -       +      -
    122A  TYR*     3.7    43.9    -      -       +      +
    125A  SER*     2.7    28.2    +      -       -      -
      8B  ALA*     4.2     6.2    -      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with GLY 62 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     58A  ARG      3.3     6.9    +      -       -      -
     59A  VAL      3.3     4.7    +      -       -      -
     60A  PHE      3.2     0.4    -      -       -      -
     61A  THR*     1.3    82.3    +      -       -      +
     63A  LEU*     1.3    62.3    +      -       -      +
     65A  LEU*     3.3    13.4    +      -       -      +
     66A  LEU*     3.4    19.8    +      -       -      +
    125A  SER*     3.7     0.6    +      -       -      -
    131A  LEU*     3.9    27.5    -      -       -      +
    236A  TYR*     3.9    12.1    -      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with LEU 63 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     59A  VAL*     3.1    28.1    +      -       +      +
     60A  PHE*     3.4    26.7    +      -       +      +
     62A  GLY*     1.3    74.4    -      -       -      +
     64A  THR*     1.3    58.5    -      -       -      +
     66A  LEU*     3.6     8.2    +      -       +      +
     67A  ASP*     3.1    32.2    +      -       -      +
    105A  TYR*     3.5    29.0    -      -       +      +
    162A  PHE*     3.6    44.9    -      -       +      +
    164A  SER*     5.9     0.4    -      -       -      +
    165A  GLY*     4.4     9.2    -      -       -      +
    166A  PHE*     4.1    20.4    -      -       +      -
    236A  TYR*     6.1     1.6    -      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with THR 64 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     60A  PHE      2.5    24.7    +      -       -      -
     61A  THR*     3.7    10.3    -      -       -      -
     62A  GLY      3.2     0.2    -      -       -      -
     63A  LEU*     1.3    75.5    -      -       -      +
     65A  LEU*     1.3    58.8    +      -       -      +
     67A  ASP*     4.0     1.9    -      -       -      +
     68A  THR*     2.5    35.0    +      -       -      -
    102A  ALA*     3.9    17.7    -      -       +      +
    105A  TYR*     3.4    22.1    -      -       +      +
    106A  SER*     5.3     0.4    -      -       -      +
    109A  PHE*     4.4     4.0    -      -       -      -
    122A  TYR*     4.2     6.5    -      -       -      +
      8B  ALA*     4.3     3.8    -      -       +      -
      9B  ILE*     3.2    39.0    -      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with LEU 65 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     61A  THR      3.4     6.4    +      -       -      +
     62A  GLY*     3.3     9.3    +      -       -      +
     63A  LEU      3.3     0.8    -      -       -      -
     64A  THR*     1.3    79.8    -      -       -      +
     66A  LEU*     1.3    59.8    +      -       +      +
     68A  THR*     3.5     3.5    +      -       -      -
     69A  LEU*     3.1    25.9    +      -       +      +
    125A  SER*     5.3     1.6    -      -       -      +
    126A  GLU*     4.6     7.9    -      -       -      +
    131A  LEU*     3.9    26.2    -      -       +      -
    132A  GLN*     3.7    24.0    -      -       -      +
    135A  ALA*     4.5    19.3    -      -       +      -
      6B  ILE*     3.5    32.7    -      -       +      +
      7B  SER*     4.2     0.2    -      -       -      -
      8B  ALA*     3.7    30.4    -      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with LEU 66 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     62A  GLY      3.4    19.4    +      -       -      +
     63A  LEU*     3.6     7.6    +      -       +      +
     64A  THR      3.3     0.2    -      -       -      -
     65A  LEU*     1.3    76.4    -      -       +      +
     67A  ASP*     1.3    60.3    +      -       -      +
     69A  LEU*     3.4    13.8    -      -       +      +
     70A  GLN*     3.1    30.3    +      -       -      +
    131A  LEU*     4.3    10.1    -      -       +      -
    134A  LYS*     3.7    41.1    -      -       +      +
    135A  ALA*     4.6    20.4    -      -       +      -
    157A  LEU*     4.2    18.6    -      -       +      +
    162A  PHE*     3.5    35.4    -      -       +      +
    236A  TYR*     6.0     0.2    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with ASP 67 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     63A  LEU      3.1    12.3    +      -       -      +
     66A  LEU*     1.3    73.9    -      -       -      +
     68A  THR*     1.3    59.8    +      -       -      +
     70A  GLN*     3.3     4.1    +      -       -      +
     71A  ASN*     3.0    27.4    +      -       -      +
     98A  GLU*     3.0    21.1    -      -       -      +
    101A  HIS*     3.5    13.8    +      -       -      +
    102A  ALA*     3.9    13.5    -      -       +      +
    105A  TYR*     3.0    29.1    +      -       -      -
    158A  GLU*     3.0     2.6    -      -       -      +
    162A  PHE*     3.3    15.6    -      -       -      -
    188A  ILE*     4.9     0.3    -      -       -      +
    320A   MN      2.2    34.7    +      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with THR 68 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     64A  THR      2.5    24.0    +      -       -      -
     65A  LEU      3.6     5.4    -      -       -      -
     67A  ASP*     1.3    75.8    -      -       -      +
     69A  LEU*     1.3    58.9    +      -       -      +
     71A  ASN*     3.3     7.5    +      -       -      +
     72A  VAL*     3.0    43.6    +      -       +      +
    102A  ALA*     4.0     4.2    -      -       -      +
      6B  ILE*     4.5     7.9    -      -       +      -
      7B  SER      3.6    21.3    -      -       -      +
      9B  ILE*     3.5    37.4    +      -       +      +
     85B  PRO*     6.2     2.0    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with LEU 69 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     65A  LEU      3.1    13.7    +      -       -      +
     66A  LEU*     3.4    15.7    -      -       +      +
     68A  THR*     1.3    78.1    -      -       -      +
     70A  GLN*     1.3    51.1    +      -       -      +
     72A  VAL      4.8     0.2    -      -       -      +
     73A  ILE*     3.0    21.0    +      -       +      +
     74A  GLY      2.7    28.6    +      -       -      -
    135A  ALA*     4.2    22.7    -      -       +      +
    138A  ILE*     4.1    24.7    -      -       +      -
    139A  GLN*     3.8    37.7    -      -       +      +
    142A  TYR*     4.4    10.3    -      -       +      -
    157A  LEU*     4.3    11.2    -      -       +      -
      6B  ILE*     4.2    20.1    -      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with GLN 70 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     66A  LEU      3.1    19.0    +      -       -      +
     67A  ASP      3.6     8.1    -      -       -      +
     68A  THR      3.3     0.2    -      -       -      -
     69A  LEU*     1.3    75.6    -      -       -      +
     71A  ASN*     1.3    61.1    +      -       -      +
     74A  GLY*     3.4     5.3    +      -       -      -
     75A  ALA*     2.9    33.4    +      -       +      +
     98A  GLU*     3.7    21.4    -      -       -      +
    142A  TYR*     2.6    39.0    +      -       -      -
    154A  SER*     3.4    21.2    +      -       -      +
    157A  LEU*     3.5    18.5    -      -       +      +
    158A  GLU*     2.9    36.0    -      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ASN 71 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     67A  ASP      3.0    17.3    +      -       -      +
     68A  THR*     3.6     8.4    -      -       -      +
     69A  LEU      3.3     0.2    -      -       -      -
     70A  GLN*     1.3    77.0    -      -       -      +
     72A  VAL*     1.3    74.9    +      -       -      +
     76A  PRO*     3.5     9.5    -      -       -      +
     95A  SER*     2.9    39.5    +      -       -      +
     98A  GLU*     3.7    13.6    -      -       +      +
     99A  ALA*     3.7    22.1    -      -       -      +
      9B  ILE*     6.1     1.2    -      -       -      +
     85B  PRO      5.7     0.2    +      -       -      -
     88B  GLU*     4.5     2.4    +      -       -      +
     89B  ALA*     4.1    15.0    -      -       -      +
     92B  SER*     2.8    30.2    +      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with VAL 72 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     68A  THR*     3.0    30.3    +      -       +      +
     71A  ASN*     1.3    89.0    -      -       -      +
     73A  ILE*     1.3    72.1    +      -       +      +
     76A  PRO*     3.4    16.8    -      -       -      +
      6B  ILE*     4.1    16.8    -      -       +      -
     79B  MET*     6.0     1.6    -      -       -      +
     88B  GLU*     4.0    35.4    -      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ILE 73 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     69A  LEU*     3.0    10.8    +      -       +      +
     72A  VAL*     1.3    90.5    -      -       +      +
     74A  GLY*     1.3    71.2    -      -       -      +
     76A  PRO*     3.4     3.6    -      -       -      +
     77A  SER*     3.1    26.4    +      -       -      -
    139A  GLN*     3.4    36.1    -      -       +      +
    142A  TYR*     3.7    28.3    -      -       +      +
    143A  ARG*     3.6    37.9    -      -       -      +
      5B  ARG*     4.9     1.8    -      -       +      -
      6B  ILE*     3.8    21.3    -      -       +      -
----------------------------------------------------------
 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