Contacts of the helix formed by residues 97 - 123 (chain D) in PDB entry 5XVO


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 97 (chain D).
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     95D  ALA      3.9     9.4    -      -       -      +
     96D  TRP*     1.3    72.5    -      -       -      +
     98D  GLU*     1.3    64.1    +      -       -      +
     99D  GLU*     3.8     4.0    +      -       -      +
    100D  ARG*     3.1    26.0    +      -       -      +
    101D  LYS*     3.1    23.1    +      -       -      +
    278D  GLN*     3.9    24.7    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with GLU 98 (chain D). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     96D  TRP      3.9     1.0    +      -       -      -
     97D  THR*     1.3    72.6    -      -       -      +
     99D  GLU*     1.3    64.2    +      -       +      +
    101D  LYS*     3.6    17.5    +      -       -      +
    102D  GLY      3.1    16.8    +      -       -      -
    142D  PHE*     3.6    26.6    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with GLU 99 (chain D). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     97D  THR*     3.2     3.9    +      -       -      +
     98D  GLU*     1.3    81.1    -      -       +      +
    100D  ARG*     1.3    57.9    +      -       -      +
    102D  GLY*     3.1     4.4    +      -       -      -
    103D  GLN*     2.9    42.9    +      -       -      +
    141D  LEU*     4.5    21.9    -      -       +      +
    142D  PHE*     5.6     0.4    -      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with ARG 100 (chain D). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     96D  TRP*     6.0     0.4    -      -       +      -
     97D  THR*     3.1    23.1    +      -       -      +
     99D  GLU*     1.3    75.6    -      -       -      +
    101D  LYS*     1.3    58.4    +      -       -      +
    103D  GLN*     2.9    27.9    +      -       -      +
    104D  VAL*     2.9    37.8    +      -       -      +
    275D  VAL*     2.8    38.0    +      -       -      +
    276D  LEU*     3.9    19.5    -      -       +      +
    278D  GLN*     3.0    42.3    -      -       +      +
    280D  GLU      4.0     8.7    +      -       -      -
    281D  GLU*     3.5    23.1    +      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with LYS 101 (chain D). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     96D  TRP*     4.0    39.6    +      -       +      +
     97D  THR      3.1    14.9    +      -       -      +
     98D  GLU*     3.8    28.7    -      -       -      +
    100D  ARG*     1.3    76.3    -      -       -      +
    102D  GLY*     1.3    53.1    +      -       -      +
    104D  VAL*     3.9     0.5    -      -       -      +
    105D  TRP*     2.7    37.8    +      -       -      +
    142D  PHE*     3.9     2.9    -      -       +      -
    201D  GLY      4.7     7.1    +      -       -      +
    202D  LEU*     4.0    38.5    +      -       +      +
    276D  LEU*     4.0    16.4    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with GLY 102 (chain D). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     98D  GLU      3.1     7.7    +      -       -      -
     99D  GLU*     3.1     7.8    +      -       -      -
    101D  LYS*     1.3    72.9    -      -       -      +
    103D  GLN*     1.3    63.1    +      -       -      +
    106D  THR*     2.6    33.0    +      -       -      -
    141D  LEU*     3.8     9.9    -      -       -      -
    142D  PHE*     3.2    33.6    -      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with GLN 103 (chain D). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     99D  GLU*     2.9    31.2    +      -       +      +
    100D  ARG*     2.9    39.2    +      -       -      +
    102D  GLY*     1.3    74.4    -      -       -      +
    104D  VAL*     1.3    59.1    +      -       +      +
    106D  THR*     3.8     2.1    -      -       -      -
    107D  ALA*     2.9    31.6    +      -       -      +
    141D  LEU*     3.9    17.6    -      -       +      +
    283D  VAL*     5.5     0.9    -      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with VAL 104 (chain D). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    100D  ARG*     2.9    26.2    +      -       -      +
    101D  LYS      3.9     2.0    -      -       -      +
    103D  GLN*     1.3    75.5    -      -       +      +
    105D  TRP*     1.3    65.2    +      -       -      +
    107D  ALA*     3.3     2.1    +      -       -      +
    108D  ILE*     3.0    42.3    +      -       +      +
    202D  LEU*     3.8    12.8    -      -       +      -
    272D  VAL*     4.0    17.3    -      -       +      -
    275D  VAL*     3.7    30.5    -      -       +      -
    276D  LEU*     3.9    17.9    -      -       +      -
    283D  VAL*     3.9    15.0    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with TRP 105 (chain D). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    101D  LYS      2.7    23.0    +      -       -      +
    102D  GLY      4.0     1.6    -      -       -      +
    104D  VAL*     1.3    72.7    -      -       -      +
    106D  THR*     1.3    74.0    +      -       +      +
    108D  ILE*     3.2     9.3    +      -       +      +
    109D  ILE*     2.9    59.4    +      -       +      +
    142D  PHE*     3.6    35.9    -      +       +      -
    143D  ASP*     3.7    20.6    -      -       +      -
    148D  GLU*     4.0    12.8    -      -       -      -
    202D  LEU*     4.0    22.2    -      -       +      +
    203D  LYS*     3.6    37.5    -      -       +      +
    216D  ASP*     3.5    39.6    +      -       +      +
    219D  GLU*     5.9     1.0    -      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with THR 106 (chain D). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    102D  GLY      2.6    22.1    +      -       -      -
    103D  GLN*     3.9     2.2    -      -       -      -
    105D  TRP*     1.3    85.0    -      -       +      +
    107D  ALA*     1.3    66.7    +      -       -      +
    109D  ILE*     3.4     2.3    +      -       -      +
    110D  ALA*     3.0    23.6    +      -       -      +
    139D  LEU*     3.8    29.6    -      -       +      +
    140D  ARG*     3.9    16.6    -      -       -      +
    141D  LEU*     3.6     7.3    -      -       +      -
    142D  PHE      3.1    22.5    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ALA 107 (chain D). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    103D  GLN      2.9    18.9    +      -       -      +
    104D  VAL      3.4     5.8    -      -       -      +
    106D  THR*     1.3    74.7    -      -       -      +
    108D  ILE*     1.3    62.8    +      -       -      +
    110D  ALA*     3.3     9.3    -      -       -      +
    111D  GLN*     3.2    27.6    +      -       -      +
    283D  VAL*     4.2    25.6    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with ILE 108 (chain D). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    104D  VAL*     3.0    34.0    +      -       +      +
    105D  TRP*     3.4    12.1    -      -       +      +
    107D  ALA*     1.3    74.4    -      -       -      +
    109D  ILE*     1.3    67.0    +      -       +      +
    111D  GLN*     3.0    22.0    +      -       -      +
    112D  LYS*     3.1     9.2    +      -       -      +
    202D  LEU*     5.0     2.9    -      -       +      -
    216D  ASP*     3.5    22.2    -      -       +      +
    217D  LEU*     4.1    26.2    -      -       +      -
    219D  GLU*     4.1     5.2    -      -       +      -
    220D  PRO*     3.7    23.3    -      -       +      +
    268D  TYR*     3.9    14.8    -      -       -      +
    272D  VAL*     4.3     8.3    -      -       +      -
    283D  VAL*     4.3    11.2    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with ILE 109 (chain D). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    105D  TRP*     2.9    52.2    +      -       +      +
    106D  THR*     3.9     2.9    -      -       -      +
    108D  ILE*     1.3    77.3    -      -       +      +
    110D  ALA*     1.3    63.8    +      -       -      +
    112D  LYS*     3.0     9.7    +      -       +      +
    113D  ILE*     2.9    39.6    +      -       +      +
    139D  LEU*     4.2    13.5    -      -       +      -
    148D  GLU*     3.2    47.8    -      -       +      +
    219D  GLU*     3.7    24.5    -      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ALA 110 (chain D). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    106D  THR*     3.0    15.1    +      -       +      +
    107D  ALA*     3.3    14.4    -      -       -      +
    109D  ILE*     1.3    77.0    -      -       -      +
    111D  GLN*     1.3    57.5    +      -       +      +
    113D  ILE*     3.2     3.4    +      -       -      +
    114D  THR*     2.8    32.7    +      -       -      +
    136D  ARG*     3.7    24.5    -      -       +      +
    139D  LEU*     4.1    15.9    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with GLN 111 (chain D). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    107D  ALA*     3.4    15.3    +      -       -      +
    108D  ILE*     3.0     9.9    +      -       -      +
    110D  ALA*     1.3    76.8    -      -       +      +
    112D  LYS*     1.3    61.3    +      -       -      +
    114D  THR*     2.5    23.5    +      -       -      +
    115D  ASN*     3.0    18.3    +      -       -      -
    220D  PRO*     4.0     9.7    -      -       +      +
    268D  TYR*     3.3    17.9    +      -       -      -
    283D  VAL*     4.1    14.5    +      -       -      +
    284D  PRO      2.8    23.2    +      -       -      +
    285D  GLU*     3.5    23.0    -      -       +      +
    286D  PHE      3.1    28.1    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with LYS 112 (chain D). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    108D  ILE      3.1     6.1    +      -       -      +
    109D  ILE*     3.0    16.9    +      -       +      +
    111D  GLN*     1.3    77.1    -      -       -      +
    113D  ILE*     1.3    52.6    +      -       +      +
    115D  ASN*     3.0     5.6    +      -       -      +
    116D  GLN*     2.8    66.1    +      -       +      +
    148D  GLU*     3.0    29.1    +      -       +      +
    152D  ALA*     5.2     6.8    -      -       -      +
    219D  GLU*     2.8    54.8    +      -       +      +
    220D  PRO*     3.8    10.2    -      -       -      +
    222D  ARG*     3.9    21.0    -      -       -      +
    223D  PRO*     4.3     3.9    -      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ILE 113 (chain D). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    109D  ILE*     2.9    32.9    +      -       +      +
    110D  ALA      3.7     6.3    -      -       -      +
    112D  LYS*     1.3    79.1    -      -       +      +
    114D  THR*     1.3    56.7    +      -       -      +
    116D  GLN*     3.1    18.1    +      -       -      +
    117D  SER*     2.9    27.5    +      -       -      -
    132D  LEU*     3.6    36.1    -      -       +      +
    133D  LEU*     4.9     0.4    -      -       -      +
    135D  MET      5.2     0.2    -      -       -      -
    136D  ARG*     4.0    17.0    -      -       +      +
    139D  LEU*     4.3    16.4    -      -       +      -
    147D  ARG*     4.6     3.4    -      -       +      +
    148D  GLU*     4.1    21.3    -      -       -      +
    151D  ALA*     4.3    15.9    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with THR 114 (chain D). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    110D  ALA      2.8    11.6    +      -       -      +
    111D  GLN*     2.5    32.0    +      -       -      +
    113D  ILE*     1.3    71.3    -      -       -      +
    115D  ASN*     1.3    61.6    +      -       -      +
    117D  SER*     3.1     8.3    +      -       -      -
    118D  LEU*     2.8    36.8    +      -       -      +
    133D  LEU*     4.6     8.6    -      -       +      +
    136D  ARG*     3.1    45.8    -      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ASN 115 (chain D). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    111D  GLN      3.0    20.2    +      -       -      +
    112D  LYS      3.5     3.6    -      -       -      +
    114D  THR*     1.3    77.1    +      -       -      +
    116D  GLN*     1.3    64.6    +      -       -      +
    118D  LEU*     3.9     7.9    -      -       -      +
    119D  HIS*     3.0    20.1    +      -       -      +
    220D  PRO*     3.0    23.4    +      -       -      +
    223D  PRO*     3.7    17.6    -      -       +      +
    286D  PHE*     3.0    25.7    +      -       -      +
    287D  GLY*     3.2    20.6    -      -       -      -
    288D  ILE*     3.3    30.4    +      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with GLN 116 (chain D). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    112D  LYS*     2.8    48.2    +      -       +      +
    113D  ILE*     3.4    25.7    -      -       -      +
    115D  ASN*     1.3    72.2    -      -       -      +
    117D  SER*     1.3    63.3    +      -       -      +
    119D  HIS*     3.3     1.8    +      -       -      -
    120D  LEU*     3.0    18.0    +      -       -      +
    132D  LEU*     3.7     6.1    -      -       +      -
    148D  GLU      4.8     1.2    -      -       -      +
    151D  ALA*     4.3    12.1    -      -       -      +
    152D  ALA*     4.1    15.0    +      -       -      +
    155D  TYR*     3.2    63.7    -      -       +      -
    156D  PHE*     4.4     4.8    -      -       -      -
    222D  ARG*     6.3     0.6    -      -       -      +
    223D  PRO*     4.3     9.0    -      -       +      -
    226D  ASP*     4.9     2.0    +      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with SER 117 (chain D). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    113D  ILE      2.9    10.7    +      -       -      -
    114D  THR      3.1     8.5    +      -       -      -
    116D  GLN*     1.3    76.6    -      -       -      +
    118D  LEU*     1.3    56.5    +      -       -      +
    120D  LEU*     2.8     7.1    +      -       -      +
    121D  ALA*     2.8    27.1    +      -       -      +
    129D  ALA*     2.7    35.8    +      -       -      +
    132D  LEU*     3.8    14.1    -      -       -      +
    133D  LEU*     3.2    26.5    -      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with LEU 118 (chain D). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    114D  THR*     2.8    23.3    +      -       -      +
    115D  ASN*     3.8    25.4    -      -       -      +
    117D  SER*     1.3    73.0    +      -       -      +
    119D  HIS*     1.3    57.4    +      -       -      +
    121D  ALA*     3.4    10.8    +      -       +      +
    122D  GLN*     2.9    28.5    +      -       -      +
    133D  LEU*     6.5     0.2    -      -       +      -
    287D  GLY*     5.1     2.5    -      -       -      -
    288D  ILE*     4.1    27.6    -      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with HIS 119 (chain D). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    115D  ASN      3.0    18.1    +      -       -      +
    116D  GLN      3.5     4.9    -      -       -      +
    118D  LEU*     1.3    73.6    -      -       -      +
    120D  LEU*     1.3    64.6    +      -       -      +
    122D  GLN*     3.2    20.0    -      -       -      +
    123D  ARG*     3.2    42.6    +      -       -      +
    155D  TYR*     2.8    28.6    +      -       -      +
    159D  LEU*     3.7    21.0    -      -       +      +
    223D  PRO*     4.7     2.0    +      -       +      -
    226D  ASP*     3.8     7.2    -      -       -      +
    227D  GLN*     3.5    39.8    -      -       +      -
    230D  TYR*     4.3     4.7    -      -       +      +
    288D  ILE*     3.9    12.5    -      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with LEU 120 (chain D). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    116D  GLN      3.0    11.7    +      -       -      +
    117D  SER      2.8     7.8    +      -       -      +
    119D  HIS*     1.3    73.0    -      -       -      +
    121D  ALA*     1.3    63.6    +      -       -      +
    123D  ARG*     2.9    15.4    +      -       -      +
    125D  TYR*     3.1    27.1    +      -       +      +
    128D  LYS*     4.1    17.3    -      -       +      +
    129D  ALA*     4.1     9.2    -      -       +      +
    132D  LEU*     3.7    38.8    -      -       +      -
    154D  SER      5.7     0.2    -      -       -      -
    155D  TYR*     3.8    17.0    -      -       +      +
    158D  THR*     3.8    30.3    -      -       +      +
    159D  LEU*     3.8    26.5    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with ALA 121 (chain D). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    117D  SER      2.8    15.0    +      -       -      +
    118D  LEU*     3.4    17.5    -      -       +      +
    120D  LEU*     1.3    71.1    -      -       -      +
    122D  GLN*     1.3    58.4    +      -       -      +
    124D  ASP*     2.8    26.7    +      -       -      +
    125D  TYR      4.5     6.1    -      -       -      +
    126D  GLY*     4.7     5.5    +      -       -      +
    129D  ALA*     3.9    15.5    -      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with GLN 122 (chain D). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    118D  LEU      2.9    15.3    +      -       -      +
    119D  HIS*     3.2    15.2    -      -       -      +
    121D  ALA*     1.3    75.4    -      -       -      +
    123D  ARG*     1.3    93.6    +      -       -      +
    124D  ASP*     3.5     7.8    +      -       -      +
    227D  GLN*     3.0    29.1    +      -       -      +
    231D  GLU*     4.5     2.3    -      -       -      +
    288D  ILE*     5.1     6.1    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with ARG 123 (chain D). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    119D  HIS*     3.2    34.9    +      -       -      +
    120D  LEU      2.9     7.9    +      -       -      +
    122D  GLN*     1.3   100.8    +      -       -      +
    124D  ASP*     1.3    70.4    +      -       -      +
    125D  TYR*     3.3    30.0    -      -       +      -
    159D  LEU*     4.2    12.1    -      -       +      -
    227D  GLN*     3.5    11.7    +      -       -      +
    230D  TYR*     3.2    36.1    -      -       +      +
    231D  GLU*     3.1    41.0    +      -       -      +
----------------------------------------------------------
 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