Contacts of the helix formed by residues 100 - 127 (chain B) in PDB entry 6AHU


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 LYS 100 (chain B).
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    101B  TYR*     1.3    63.0    +      -       -      +
    102B  ILE*     3.4     7.2    -      -       -      +
    103B  THR*     3.4    21.3    +      -       +      +
    104B  ALA*     2.9    29.2    +      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with TYR 101 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    100B  LYS*     1.3    77.0    -      -       -      +
    102B  ILE*     1.3    68.9    +      -       +      +
    104B  ALA*     4.4     7.2    -      -       +      +
    105B  SER*     2.9    52.2    +      -       -      -
     18E  PRO*     3.5    41.9    -      -       +      +
     21E  ARG*     2.4    38.6    +      -       +      -
     22E  LEU*     6.5     1.6    -      -       +      -
     61E  TYR      6.1     0.4    -      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with ILE 102 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    100B  LYS*     4.9     3.8    -      -       -      -
    101B  TYR*     1.3    88.2    -      -       +      +
    103B  THR*     1.3    82.4    +      -       -      +
    105B  SER*     4.0     5.2    +      -       -      -
    106B  THR*     2.9    23.4    +      -       -      -
    129E  CYS*     5.3     7.9    -      -       -      -
    131E  ASP*     3.6    19.1    -      -       -      +
    134E  GLU*     3.2    41.2    -      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with THR 103 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    100B  LYS*     3.4    24.3    +      -       +      +
    101B  TYR      3.2     0.6    -      -       -      -
    102B  ILE*     1.3    92.5    -      -       -      +
    104B  ALA*     1.3    64.0    +      -       -      +
    106B  THR*     3.1    17.2    +      -       -      -
    107B  PHE*     3.2    35.0    -      -       +      -
    131E  ASP*     5.4     0.3    +      -       -      -
    133E  GLY      5.4     5.6    +      -       -      +
    134E  GLU*     5.1     8.7    +      -       -      +
    137E  ALA*     5.3     8.7    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with ALA 104 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    100B  LYS*     2.9    19.0    +      -       +      +
    101B  TYR*     4.1     9.4    -      -       +      +
    103B  THR*     1.3    76.3    -      -       -      +
    105B  SER*     1.3    61.7    +      -       -      +
    106B  THR      3.4     0.3    +      -       -      -
    107B  PHE*     3.5    21.3    +      -       -      +
    108B  ALA*     3.6    10.6    +      -       -      +
     61E  TYR*     5.8     5.5    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with SER 105 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    101B  TYR*     2.9    49.4    +      -       -      -
    102B  ILE*     4.3     6.5    -      -       -      -
    103B  THR      3.3     0.4    -      -       -      -
    104B  ALA*     1.3    76.0    -      -       -      +
    106B  THR*     1.3    63.2    +      -       -      +
    107B  PHE      3.4     0.2    -      -       -      -
    108B  ALA*     3.6     6.5    +      -       -      +
    109B  GLN*     3.2    41.0    +      -       -      +
     21E  ARG*     4.8     5.2    +      -       -      -
     61E  TYR      5.2     6.6    +      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with THR 106 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    102B  ILE      2.9    17.5    +      -       -      -
    103B  THR      3.1    10.1    +      -       -      -
    105B  SER*     1.3    77.5    -      -       -      +
    107B  PHE*     1.3    60.0    +      -       +      +
    109B  GLN*     3.8     5.5    -      -       -      +
    110B  ALA*     2.9    30.5    +      -       +      +
    122E  LEU*     5.2     6.1    -      -       +      +
    125E  LEU*     5.3     2.1    -      -       -      +
    134E  GLU*     3.8    14.6    +      -       -      +
    137E  ALA*     3.7    37.9    -      -       +      +
    138E  ILE*     3.8    21.5    -      -       +      +
    141E  SER*     5.2     2.2    -      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with PHE 107 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    103B  THR*     3.2    45.8    -      -       +      -
    104B  ALA*     3.5    13.7    +      -       -      +
    105B  SER      3.4     0.2    -      -       -      -
    106B  THR*     1.3    78.2    -      -       +      +
    108B  ALA*     1.3    62.0    +      -       -      +
    110B  ALA*     4.1     5.1    -      -       +      +
    111B  ARG*     3.3    44.6    +      -       -      +
    137E  ALA*     5.3    11.0    -      -       +      -
    140E  LYS*     5.4    17.5    -      -       +      -
    144E  ARG*     5.5    10.3    -      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with ALA 108 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    104B  ALA      3.6     9.8    +      -       -      +
    105B  SER*     3.6     8.2    +      -       -      +
    106B  THR      3.2     0.4    -      -       -      -
    107B  PHE*     1.3    80.6    -      -       -      +
    109B  GLN*     1.3    58.2    +      -       +      +
    111B  ARG*     3.4     6.3    +      -       -      +
    112B  ALA*     2.9    27.4    +      -       -      +
     61E  TYR*     3.7    31.9    -      -       +      +
     62E  THR*     3.6    19.7    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with GLN 109 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    105B  SER*     3.2    27.5    +      -       -      +
    106B  THR*     4.2     4.8    -      -       -      +
    108B  ALA*     1.3    75.9    -      -       +      +
    110B  ALA*     1.3    63.0    +      -       -      +
    112B  ALA*     4.0     6.7    -      -       -      -
    113B  ALA*     3.4     2.4    +      -       -      +
     21E  ARG*     5.6     5.9    -      -       -      +
     62E  THR*     4.8    16.9    +      -       +      +
    118E  ASN*     2.5    40.3    +      -       -      +
    121E  GLN*     3.1    37.5    +      -       -      +
    122E  LEU*     3.3    27.0    -      -       +      +
    125E  LEU*     4.5    12.2    -      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ALA 110 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    106B  THR*     2.9    19.5    +      -       +      +
    107B  PHE*     4.1     5.6    -      -       +      +
    109B  GLN*     1.3    76.8    -      -       -      +
    111B  ARG*     1.3    59.4    +      -       +      +
    113B  ALA*     3.2     8.7    +      -       -      +
    114B  GLU*     3.1    36.5    +      -       -      +
    122E  LEU*     5.4     2.3    -      -       -      +
    137E  ALA      5.7     0.2    -      -       -      +
    140E  LYS      5.7     0.2    -      -       -      +
    141E  SER*     3.8    32.5    -      -       -      -
    144E  ARG*     6.4     1.1    -      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ARG 111 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    107B  PHE*     3.3    31.5    +      -       -      +
    108B  ALA*     3.9     4.9    -      -       -      +
    110B  ALA*     1.3    75.2    -      -       +      +
    112B  ALA*     1.3    60.1    +      -       -      +
    113B  ALA      3.2     0.2    -      -       -      -
    114B  GLU*     3.5    19.7    -      -       -      +
    115B  ILE*     2.9    50.2    +      -       +      +
    144E  ARG*     5.9     5.6    -      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ALA 112 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    108B  ALA      2.9    17.0    +      -       -      +
    109B  GLN*     3.7     4.0    -      -       -      +
    110B  ALA      3.2     0.2    -      -       -      -
    111B  ARG*     1.3    78.5    -      -       -      +
    113B  ALA*     1.3    56.0    +      -       -      +
    115B  ILE*     5.2     1.6    -      -       -      -
    116B  SER*     3.1    31.1    +      -       -      +
     57E  TYR*     4.9    10.1    -      -       -      +
     59E  ASN*     5.2     3.6    -      -       -      +
     62E  THR*     4.4    18.6    -      -       +      +
    114E  LEU*     3.9    14.4    -      -       +      +
    115E  ILE*     5.2     0.2    -      -       -      +
    118E  ASN*     3.5    18.4    -      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ALA 113 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    109B  GLN      4.0     1.8    -      -       -      +
    110B  ALA*     3.2    11.8    +      -       -      +
    112B  ALA*     1.3    77.0    -      -       -      +
    114B  GLU*     1.3    60.1    +      -       +      +
    116B  SER*     5.1     1.1    -      -       -      -
    117B  ALA*     3.3    24.9    +      -       -      +
    115E  ILE*     5.0    16.8    -      -       +      +
    118E  ASN*     3.2    23.7    -      -       +      +
    119E  ARG*     5.8     6.3    -      -       +      +
    145E  SER*     5.6     9.4    -      -       -      -
    148E  LEU*     3.7     5.2    -      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with GLU 114 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    110B  ALA*     3.1    24.9    +      -       -      +
    111B  ARG*     3.2    22.4    +      -       -      +
    113B  ALA*     1.3    79.2    -      -       +      +
    115B  ILE*     1.3    60.9    +      -       +      +
    116B  SER      3.4     0.4    -      -       -      -
    117B  ALA*     3.3     2.4    +      -       -      +
    118B  MET*     2.9    48.8    +      -       +      +
    141E  SER*     5.9     0.6    -      -       -      +
    144E  ARG*     3.3    43.2    +      -       +      +
    145E  SER*     5.5     1.6    -      -       -      +
    148E  LEU*     3.8    23.5    -      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ILE 115 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    111B  ARG*     2.9    37.9    +      -       +      +
    112B  ALA*     5.1     2.0    -      -       -      +
    114B  GLU*     1.3    73.9    -      -       +      +
    116B  SER*     1.3    59.4    +      -       -      +
    118B  MET*     3.3    17.0    +      -       +      +
    119B  LEU*     2.8    39.9    +      -       +      +
     57E  TYR*     5.4    13.7    -      -       +      +
     59E  ASN*     6.0     5.4    -      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with SER 116 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    112B  ALA      3.1    21.1    +      -       -      -
    114B  GLU      3.4     0.2    -      -       -      -
    115B  ILE*     1.3    78.7    -      -       -      +
    117B  ALA*     1.3    60.1    +      -       -      +
    119B  LEU*     3.9     4.4    +      -       -      +
    120B  LYS*     3.4    24.3    +      -       -      +
     57E  TYR*     4.0     7.6    +      -       -      -
    111E  GLN*     2.9    37.6    +      -       -      +
    114E  LEU*     3.4    15.0    -      -       -      +
    115E  ILE*     4.0    19.5    -      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ALA 117 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    113B  ALA      3.3    21.0    +      -       -      +
    114B  GLU      3.3     4.4    +      -       -      +
    115B  ILE      3.2     0.4    -      -       -      -
    116B  SER*     1.3    80.0    -      -       -      +
    118B  MET*     1.3    58.6    +      -       -      +
    120B  LYS*     3.3    10.8    -      -       +      +
    121B  ALA*     3.2    27.9    +      -       -      +
    115E  ILE*     4.2    10.7    -      -       +      +
    119E  ARG*     6.4     0.4    -      -       -      +
    148E  LEU*     3.8    20.4    -      -       +      -
     60G  ALA*     5.8     6.6    -      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with MET 118 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    114B  GLU*     2.9    41.4    +      -       +      +
    115B  ILE*     3.3    15.0    +      -       +      +
    117B  ALA*     1.3    75.1    -      -       -      +
    119B  LEU*     1.3    64.2    +      -       -      +
    120B  LYS      3.2     0.9    -      -       -      -
    121B  ALA*     3.9     5.4    -      -       +      +
    122B  VAL*     3.3    35.4    +      -       +      +
    148E  LEU*     4.1    21.1    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with LEU 119 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    273A    C      5.1    18.2    -      -       +      +
    115B  ILE*     2.8    27.0    +      -       +      +
    116B  SER*     4.2     6.1    -      -       -      +
    117B  ALA      3.3     0.4    -      -       -      -
    118B  MET*     1.3    79.4    -      -       -      +
    120B  LYS*     1.3    55.4    +      -       +      +
    123B  THR*     2.5    32.7    +      -       +      +
     57E  TYR*     5.9     7.2    -      -       +      -
    107E  ILE*     4.6    13.9    -      -       +      -
    108E  ARG*     6.2     2.2    -      -       +      -
    111E  GLN*     4.2    30.1    -      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with LYS 120 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    116B  SER      3.4    15.8    +      -       -      +
    117B  ALA*     3.3    16.4    -      -       +      +
    119B  LEU*     1.3    82.0    -      -       +      +
    121B  ALA*     1.3    59.8    +      -       -      +
    122B  VAL      3.7     0.2    -      -       -      -
    123B  THR*     4.2     2.5    -      -       -      -
    124B  GLN*     3.3    42.4    +      -       -      +
    108E  ARG*     3.8    24.4    +      -       +      +
    111E  GLN*     5.4     3.4    -      -       +      -
    112E  LYS*     3.7    39.9    -      -       +      +
    115E  ILE*     3.9    19.7    -      -       +      -
     59G  GLY      4.1     4.3    +      -       -      +
     60G  ALA*     3.2    40.5    +      -       +      +
     61G  ARG*     4.8     2.3    -      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ALA 121 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    117B  ALA      3.2    18.3    +      -       -      +
    118B  MET*     3.7     4.7    +      -       -      -
    119B  LEU      3.6     0.2    -      -       -      -
    120B  LYS*     1.3    80.3    -      -       +      +
    122B  VAL*     1.3    65.8    +      -       +      +
    123B  THR      3.3     0.6    +      -       -      -
    124B  GLN*     3.6     9.3    +      -       -      +
    125B  LYS*     3.6    26.9    +      -       -      +
     60G  ALA*     5.5    10.1    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with VAL 122 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    118B  MET*     3.3    26.5    +      -       +      +
    121B  ALA*     1.3    78.9    -      -       +      +
    123B  THR*     1.3    53.4    +      -       -      +
    125B  LYS*     3.0    10.6    +      -       +      +
    126B  SER*     2.7    38.4    +      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with THR 123 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    272A    U      5.8     0.2    -      -       -      -
    273A    C      3.8    21.5    -      -       -      +
    119B  LEU*     2.5    31.0    +      -       +      +
    120B  LYS      4.6     0.2    -      -       -      -
    121B  ALA      3.3     0.6    -      -       -      -
    122B  VAL*     1.3    79.8    -      -       -      +
    124B  GLN*     1.3    60.7    +      -       -      +
    126B  SER*     4.1     9.0    -      -       -      -
    127B  SER*     3.1    22.1    +      -       -      +
    128B  ASN      6.0     1.3    -      -       -      +
    108E  ARG*     3.4    31.4    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with GLN 124 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    272A    U      4.8    16.2    -      -       +      +
    120B  LYS*     3.3    34.0    +      -       -      +
    121B  ALA*     3.6    10.2    +      -       -      +
    122B  VAL      3.3     0.4    -      -       -      -
    123B  THR*     1.3    79.0    -      -       -      +
    125B  LYS*     1.3    60.3    +      -       +      +
    126B  SER      3.7     0.2    +      -       -      -
    127B  SER*     4.4     8.8    +      -       -      -
    134B  THR*     5.4     3.8    -      -       -      +
    108E  ARG*     3.4    22.6    -      -       -      +
    112E  LYS*     5.4     7.7    -      -       -      +
     60G  ALA      5.1     5.7    +      -       -      +
     61G  ARG*     6.1     2.0    -      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with LYS 125 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    121B  ALA*     3.6    14.5    +      -       -      +
    122B  VAL*     3.0    12.1    +      -       +      +
    124B  GLN*     1.3    78.3    -      -       +      +
    126B  SER*     1.3    62.6    +      -       -      +
    127B  SER*     5.1     0.2    -      -       -      -
    134B  THR*     3.5    27.5    +      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with SER 126 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    122B  VAL*     2.7    24.2    +      -       -      -
    123B  THR*     3.4    11.4    +      -       -      -
    125B  LYS*     1.3    76.5    -      -       -      +
    127B  SER*     1.3    70.9    +      -       -      +
    128B  ASN*     4.0     2.1    +      -       -      -
    129B  SER*     3.1    25.2    +      -       -      +
    130B  LEU      3.3    22.2    +      -       -      +
    134B  THR*     3.9     0.2    +      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with SER 127 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    272A    U      4.7    21.3    +      -       -      +
    273A    C      6.0     0.7    -      -       -      -
    123B  THR*     3.1    13.3    +      -       -      -
    124B  GLN      4.5     9.4    -      -       -      -
    126B  SER*     1.3    81.2    -      -       -      +
    128B  ASN*     1.3    70.5    +      -       -      +
    130B  LEU*     3.3    15.9    +      -       -      +
    133B  GLN*     3.3    44.7    +      -       -      +
    134B  THR*     4.7     2.2    -      -       -      -
    108E  ARG*     5.7     2.2    -      -       -      +
----------------------------------------------------------
 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