Contacts of the helix formed by residues 168 - 193 (chain A) in PDB entry 5LXG


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 GLN 168 (chain A).
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    166A  PRO*     3.1    27.8    +      -       +      +
    167A  LEU*     1.3    76.2    -      -       -      +
    169A  GLU*     1.3    61.8    +      -       -      +
    170A  LYS      3.2     2.2    +      -       -      -
    171A  VAL*     3.3    25.0    +      -       +      +
    172A  VAL*     4.3     3.7    +      -       -      +
    225A  TYR*     4.2    19.4    +      -       +      +
----------------------------------------------------------
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Residues in contact with GLU 169 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    164A  MET*     4.9    17.6    -      -       +      +
    165A  ALA      2.0    40.1    +      -       -      +
    166A  PRO*     3.6    10.8    -      -       +      +
    167A  LEU*     4.8     3.1    -      -       -      +
    168A  GLN*     1.3    74.0    -      -       -      +
    170A  LYS*     1.3    61.3    +      -       -      +
    171A  VAL      3.3     0.4    -      -       -      -
    172A  VAL*     3.2    20.2    +      -       -      +
    173A  PHE*     3.2    17.2    +      -       -      -
    225A  TYR*     3.9    15.9    +      -       +      -
    226A  TYR*     2.3    49.3    +      -       -      +
    229A  TYR*     4.2     9.7    -      -       -      -
    359A  GLN*     5.0     6.1    +      -       -      +
    363A  TYR*     6.0     0.9    -      -       -      -
----------------------------------------------------------
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Residues in contact with LYS 170 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    155A  THR*     2.6    33.5    +      -       -      +
    156A  MET*     2.8    49.4    +      -       -      +
    158A  ARG*     3.6    18.0    -      -       -      +
    161A  MET*     4.9    23.6    -      -       +      -
    164A  MET*     4.9    17.3    -      -       +      +
    167A  LEU*     3.6    19.4    +      -       -      +
    168A  GLN      3.2     1.2    -      -       -      -
    169A  GLU*     1.3    74.8    -      -       -      +
    171A  VAL*     1.4    55.9    +      -       +      +
    173A  PHE*     3.3     6.8    +      -       +      +
    174A  GLY*     2.8    32.7    +      -       -      -
----------------------------------------------------------
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Residues in contact with VAL 171 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    167A  LEU      5.6     0.9    -      -       -      +
    168A  GLN*     3.3    15.9    +      -       +      +
    169A  GLU      3.3     0.4    -      -       -      -
    170A  LYS*     1.4    75.8    -      -       +      +
    172A  VAL*     1.3    60.0    +      -       +      +
    174A  GLY*     3.2     2.5    +      -       -      +
    175A  MET*     2.9    53.1    +      -       +      +
    221A  VAL*     6.5     0.2    -      -       +      -
----------------------------------------------------------
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Residues in contact with VAL 172 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    168A  GLN      4.8     3.1    -      -       -      +
    169A  GLU*     3.2    15.9    +      -       -      +
    171A  VAL*     1.3    79.2    -      -       +      +
    173A  PHE*     1.3    61.0    +      -       +      +
    175A  MET*     3.7     3.3    +      -       -      +
    176A  PHE      3.6     7.1    +      -       -      -
    221A  VAL*     3.5    20.6    -      -       +      +
    222A  PRO*     2.8    59.8    -      -       +      +
    225A  TYR*     3.8    42.8    -      -       +      -
    226A  TYR*     4.8     5.6    -      -       -      +
----------------------------------------------------------
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Residues in contact with PHE 173 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    155A  THR*     4.5    13.9    -      -       +      -
    156A  MET*     5.0     4.5    -      -       +      -
    164A  MET*     5.6    12.1    -      -       +      -
    169A  GLU*     3.2    10.3    +      -       +      +
    170A  LYS*     3.8     8.7    -      -       +      +
    172A  VAL*     1.3    76.3    -      -       +      +
    174A  GLY*     1.3    63.6    +      -       -      +
    176A  PHE*     3.2    10.8    +      +       -      +
    177A  PHE*     3.0    42.8    +      +       +      -
    222A  PRO*     4.7     8.1    -      -       +      -
    226A  TYR*     3.4    43.1    -      +       -      -
    352A  PHE*     3.4    37.9    -      +       -      -
    355A  VAL*     4.2    16.4    -      -       +      -
    356A  SER*     4.1    16.6    -      -       -      -
    359A  GLN*     5.2    10.8    -      -       -      -
----------------------------------------------------------
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Residues in contact with GLY 174 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    156A  MET*     3.7    18.8    -      -       -      +
    170A  LYS      2.8    18.4    +      -       -      -
    171A  VAL*     3.2     4.7    +      -       -      -
    173A  PHE*     1.3    69.9    -      -       -      +
    175A  MET*     1.4    58.0    +      -       -      +
    177A  PHE*     3.1     7.2    +      -       -      +
    178A  LEU*     2.9    35.7    +      -       -      +
----------------------------------------------------------
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Residues in contact with MET 175 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    171A  VAL*     2.9    38.3    +      -       +      +
    172A  VAL*     3.8     7.9    -      -       -      +
    173A  PHE      3.4     0.2    -      -       -      -
    174A  GLY*     1.4    72.5    -      -       -      +
    176A  PHE*     1.3    62.3    +      -       -      +
    178A  LEU*     3.4    14.8    +      -       +      +
    179A  GLY*     3.2    17.3    +      -       -      -
    218A  GLY*     3.8     9.4    -      -       -      -
    221A  VAL*     3.9    36.6    -      -       +      -
----------------------------------------------------------
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Residues in contact with PHE 176 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    148A  PHE*     3.8    25.6    -      +       -      -
    172A  VAL      3.6     2.0    +      -       -      +
    173A  PHE*     3.2    12.1    +      +       -      +
    175A  MET*     1.3    78.5    -      -       -      +
    177A  PHE*     1.3    79.3    +      +       -      +
    179A  GLY*     3.3     2.9    +      -       -      -
    180A  ALA*     3.0    27.0    +      -       +      +
    215A  LEU*     4.4     9.4    -      -       +      +
    218A  GLY*     3.3    16.5    +      -       -      +
    219A  SER*     3.4    38.1    -      -       -      -
    222A  PRO*     3.7    16.2    -      -       +      -
    348A  ALA*     3.6    26.5    -      -       +      -
    351A  HIS*     3.5    16.6    -      +       +      -
    352A  PHE*     4.3    17.7    -      +       +      -
    355A  VAL*     6.0     1.6    -      -       +      -
----------------------------------------------------------
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Residues in contact with PHE 177 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    148A  PHE*     3.4    37.5    -      +       -      +
    151A  LEU*     3.4    38.4    -      -       +      -
    152A  GLY*     3.5    22.7    -      -       -      -
    155A  THR*     4.3     7.6    -      -       +      -
    156A  MET*     5.0     2.0    -      -       +      -
    173A  PHE*     3.0    46.6    +      +       +      -
    174A  GLY*     3.1    10.2    +      -       -      +
    176A  PHE*     1.3    86.1    -      +       -      +
    178A  LEU*     1.4    55.7    +      -       -      +
    180A  ALA*     3.8     2.4    -      -       -      +
    181A  VAL*     2.8    42.3    +      -       +      +
    352A  PHE*     3.9    23.8    -      +       -      -
----------------------------------------------------------
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Residues in contact with LEU 178 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    174A  GLY      2.9    16.3    +      -       -      +
    175A  MET*     3.7    16.4    -      -       -      +
    177A  PHE*     1.4    74.1    -      -       -      +
    179A  GLY*     1.3    53.7    +      -       -      +
    181A  VAL*     4.6     6.3    -      -       +      -
    182A  LEU*     2.7    61.8    +      -       +      +
----------------------------------------------------------
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Residues in contact with GLY 179 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    175A  MET      3.2    10.2    +      -       -      -
    176A  PHE      3.7     3.1    -      -       -      -
    178A  LEU*     1.3    79.1    -      -       -      +
    180A  ALA*     1.3    54.9    +      -       -      +
    182A  LEU*     4.1     1.9    -      -       -      +
    183A  CYS*     2.9    33.6    +      -       -      +
    211A  GLY      4.2     0.5    -      -       -      +
    214A  LEU*     3.7    30.2    -      -       -      +
    215A  LEU*     3.9     8.6    +      -       -      -
    218A  GLY*     5.0     0.4    -      -       -      -
----------------------------------------------------------
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Residues in contact with ALA 180 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    148A  PHE*     3.7    33.7    -      -       +      -
    176A  PHE*     3.0    19.6    +      -       +      +
    177A  PHE*     3.8     4.5    -      -       -      +
    179A  GLY*     1.3    72.7    -      -       -      +
    181A  VAL*     1.3    56.8    +      -       -      +
    183A  CYS*     3.7     1.5    -      -       -      +
    184A  LEU*     2.9    41.1    +      -       +      +
    215A  LEU*     3.6    24.9    -      -       +      +
    348A  ALA*     5.1     2.0    -      -       +      -
----------------------------------------------------------
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Residues in contact with VAL 181 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    145A  PHE*     3.7    28.8    -      -       +      +
    148A  PHE*     3.9    10.1    -      -       +      +
    149A  LEU*     3.7    42.2    -      -       +      +
    152A  GLY*     6.2     0.2    -      -       -      -
    177A  PHE*     2.8    25.8    +      -       +      +
    178A  LEU*     3.9     8.1    -      -       +      +
    180A  ALA*     1.3    72.9    -      -       -      +
    182A  LEU*     1.3    60.6    +      -       +      +
    184A  LEU*     3.4     5.2    +      -       -      -
    185A  SER*     2.8    36.3    +      -       -      +
----------------------------------------------------------
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Residues in contact with LEU 182 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    178A  LEU*     2.7    47.9    +      -       +      +
    179A  GLY*     4.1     2.7    -      -       -      +
    181A  VAL*     1.3    74.1    -      -       +      +
    183A  CYS*     1.3    55.9    +      -       -      +
    185A  SER*     2.8    21.5    +      -       -      +
    186A  PHE*     2.8    54.8    +      -       +      -
    214A  LEU*     4.1    21.1    -      -       +      -
----------------------------------------------------------
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Residues in contact with CYS 183 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    141A  HIS*     5.1     6.5    -      -       -      -
    179A  GLY      2.9    20.0    +      -       -      +
    180A  ALA*     3.7     4.0    -      -       -      +
    182A  LEU*     1.3    76.0    -      -       -      +
    184A  LEU*     1.3    58.0    -      -       -      +
    186A  PHE*     3.9     2.1    -      -       -      +
    187A  SER*     3.1    30.4    +      -       -      -
    208A  ASP*     4.6     2.7    -      -       -      +
    211A  GLY*     3.1    37.7    +      -       -      +
    212A  ILE*     3.8    17.9    -      -       -      -
    215A  LEU*     3.9    23.1    -      -       +      -
    344A  VAL*     4.9     8.1    -      -       -      -
----------------------------------------------------------
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Residues in contact with LEU 184 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    141A  HIS*     3.5    38.9    -      -       +      +
    144A  GLY*     3.7    26.5    -      -       -      +
    145A  PHE*     3.9    15.0    -      -       +      -
    148A  PHE*     3.8    22.7    -      -       +      -
    180A  ALA*     2.9    36.3    +      -       +      +
    181A  VAL*     3.7     4.3    -      -       -      +
    183A  CYS*     1.3    75.6    -      -       +      +
    185A  SER*     1.3    63.0    +      -       -      +
    187A  SER*     3.5     2.8    +      -       -      -
    188A  TRP*     3.2    26.7    +      -       -      -
    215A  LEU*     6.3     1.1    -      -       +      -
    344A  VAL*     5.2     4.9    -      -       +      -
    345A  VAL*     3.9    22.2    -      -       +      -
    348A  ALA*     6.2     0.9    -      -       +      -
----------------------------------------------------------
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Residues in contact with SER 185 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    145A  PHE*     3.8    20.3    -      -       -      -
    181A  VAL*     2.8    19.9    +      -       -      -
    182A  LEU*     2.8    28.8    +      -       -      +
    184A  LEU*     1.3    69.1    -      -       -      +
    186A  PHE*     1.4    71.2    +      -       -      +
    188A  TRP*     3.3    17.7    -      -       -      +
    189A  LEU*     3.2    34.9    +      -       -      +
----------------------------------------------------------
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Residues in contact with PHE 186 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    182A  LEU*     2.8    54.8    +      -       +      +
    183A  CYS*     3.9     3.8    -      -       -      +
    185A  SER*     1.4    80.7    +      -       -      +
    187A  SER*     1.3    57.8    +      -       -      +
    189A  LEU*     3.4    11.9    +      -       +      +
    190A  PHE*     2.9    32.1    +      -       -      +
    204A  PHE*     5.0     2.3    -      -       -      +
    207A  LEU*     3.4    66.0    -      -       +      +
    208A  ASP*     4.3     4.6    -      -       -      +
    210A  SER*     5.2     1.8    -      -       -      -
    211A  GLY*     3.7    11.4    -      -       -      -
    214A  LEU*     4.2    15.5    -      -       +      -
----------------------------------------------------------
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Residues in contact with SER 187 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    141A  HIS*     3.3    24.3    -      -       -      -
    183A  CYS*     3.1    15.9    +      -       -      -
    184A  LEU      3.7     1.1    -      -       -      -
    185A  SER      3.3     0.2    -      -       -      -
    186A  PHE*     1.3    74.3    -      -       -      +
    188A  TRP*     1.3    63.3    +      -       -      +
    190A  PHE*     3.9     0.3    -      -       -      +
    191A  HIS*     2.8    30.9    +      -       -      -
    208A  ASP*     3.4    15.5    +      -       -      -
    341A  HIS*     2.6    35.8    -      -       -      -
    401A   ZN      3.3     6.9    -      -       -      -
----------------------------------------------------------
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Residues in contact with TRP 188 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    125A  PHE*     4.0    18.8    -      +       -      -
    128A  ILE*     4.2     9.9    -      -       +      -
    137A  ASN      4.8     0.4    -      -       -      -
    138A  ILE*     3.4    32.0    -      -       +      +
    141A  HIS*     4.0    13.6    -      -       +      +
    142A  LEU*     3.6    35.9    -      -       +      +
    145A  PHE*     4.2    17.5    -      +       +      -
    184A  LEU      3.2    25.8    +      -       -      +
    185A  SER*     3.3    24.9    -      -       -      +
    187A  SER*     1.3    77.1    -      -       -      +
    189A  LEU*     1.4    78.3    +      -       +      +
    191A  HIS*     3.5     3.3    +      -       -      +
    192A  THR*     2.8    49.7    +      -       +      +
----------------------------------------------------------
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Residues in contact with LEU 189 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    125A  PHE*     4.0    20.4    -      -       +      -
    185A  SER*     3.2    29.9    +      -       -      +
    186A  PHE*     3.7    13.9    -      -       +      +
    188A  TRP*     1.4   107.1    -      -       +      +
    190A  PHE*     1.3    64.8    +      -       -      +
    192A  THR*     2.6    19.7    +      -       -      +
    193A  VAL*     3.1    16.3    +      -       +      +
    204A  PHE*     3.8    24.9    -      -       +      -
    207A  LEU*     6.0     0.4    -      -       +      -
----------------------------------------------------------
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Residues in contact with PHE 190 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    106A  ASP*     5.7     0.9    -      -       -      -
    186A  PHE      2.9    18.1    +      -       -      +
    187A  SER      3.9     1.1    -      -       -      +
    189A  LEU*     1.3    75.7    -      -       -      +
    191A  HIS*     1.3    90.1    +      +       -      +
    193A  VAL*     3.6     1.4    -      -       -      +
    194A  TYR*     3.0    63.6    +      +       -      +
    201A  SER*     3.8     8.7    -      -       -      -
    204A  PHE*     3.6    26.8    -      -       +      +
    205A  SER*     3.4    43.3    -      -       -      -
    208A  ASP*     3.7    20.2    -      -       +      -
    337A  HIS*     5.6     1.6    -      +       -      -
----------------------------------------------------------
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Residues in contact with HIS 191 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    115A  ARG*     2.7    31.9    +      -       -      -
    134A  GLU*     2.8    26.9    +      -       -      +
    137A  ASN*     3.3    14.1    -      -       +      +
    138A  ILE*     3.4    21.9    -      -       +      +
    187A  SER*     2.8    29.8    +      -       -      +
    188A  TRP      3.9     2.5    -      -       -      +
    189A  LEU      3.3     0.2    -      -       -      -
    190A  PHE*     1.3    97.4    -      +       -      +
    192A  THR*     1.4    51.6    +      -       -      +
    194A  TYR*     3.3     8.3    -      -       -      +
    337A  HIS*     2.9    31.6    +      +       -      -
    341A  HIS*     3.2     5.0    +      +       -      -
    401A   ZN      2.3    29.5    -      -       -      -
----------------------------------------------------------
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Residues in contact with THR 192 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    115A  ARG*     3.0    21.7    +      -       -      +
    124A  CYS*     3.4    26.0    -      -       -      +
    125A  PHE*     4.2    10.1    -      -       -      -
    128A  ILE*     3.7    15.5    -      -       +      -
    138A  ILE*     3.5    33.0    -      -       +      -
    188A  TRP*     2.8    31.4    +      -       +      +
    189A  LEU*     2.6    23.2    +      -       -      -
    191A  HIS*     1.4    76.0    -      -       -      +
    193A  VAL*     1.3    64.1    +      -       -      +
    194A  TYR      3.3     2.5    +      -       -      -
----------------------------------------------------------
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Residues in contact with VAL 193 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    121A  PHE*     3.9    32.8    -      -       +      -
    124A  CYS*     4.2    10.1    -      -       +      -
    125A  PHE*     4.5    15.0    -      -       +      -
    189A  LEU*     3.1    16.7    +      -       +      +
    190A  PHE*     3.8     5.2    -      -       +      +
    192A  THR*     1.3    88.8    +      -       -      +
    194A  TYR*     1.3    61.2    +      -       -      +
    195A  CYS      3.3     2.5    -      -       -      -
    196A  HIS*     3.2    18.9    +      -       +      +
    200A  VAL*     4.0     8.0    -      -       +      +
    201A  SER      4.6     3.8    +      -       -      -
    204A  PHE*     3.5    43.1    -      -       +      -
----------------------------------------------------------
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A short description of the analytical approach
The contact analysis used in this page is based upon the approach developed in: Sobolev V., Wade R.C., Vriend G. and Edelman M. PROTEINS (1996) 25, 120-129. Contact legitimacy depends on the hydrophobic-hydrophilic properties of the contacting atoms. In order to define it, for each inter-atomic contact, eight atom classes have been introduced:


   I  Hydrophilic      - N and O that can donate and accept hydrogen bonds
                         (e.g., oxygen of hydroxyl group of Ser. or Thr)
  II  Acceptor         - N or O that can only accept a hydrogen bond
 III  Donor            - N that can only donate a hydrogen bond
  IV  Hydrophobic      - Cl, Br, I and all C atoms that are not in
                         aromatic rings and do not have a covalent bond to
                         a N or O atom
   V  Aromatic         - C in aromatic rings irrespective of any other 
                         bonds formed by the atom
  VI  Neutral          - C atoms that have a covalent bond to at least one
                         atom of class I or two or more atoms from class II
                         or III; atoms; S, F, P, and metal atoms in all cases
 VII  Neutral-donor    - C atoms that have a covalent bond with only one
                         atom of class III
VIII  Neutral-acceptor - C atoms that have a covalent bond with only 
                         one atom of class II
For each pair of contacts the state of legitimacy is shown below:

Legend:
+, legitimate
-, illegitimate
------------------------------------------------------------
  Atomic class           I  II  III   IV   V   VI  VII  VIII
------------------------------------------------------------
   I  (Hydrophilic)      +   +    +    -   +   +    +    +
  II  (Acceptor)         +   -    +    -   +   +    +    -
 III  (Donor)            +   +    -    -   +   +    -    +
  IV  (Hydrophobic)      -   -    -    +   +   +    +    +
   V  (Aromatic)         +   +    +    +   +   +    +    +
  VI  (Neutral)          +   +    +    +   +   +    +    +
 VII  (Neutral-donor)    +   +    -    +   +   +    -    +
VIII  (Neutral-acceptor) +   -    +    +   +   +    +    -
------------------------------------------------------------
Warning!
Atom classes for heterogroups are automatically assigned based on the atomic coordinates. However, in three cases (see below) the automatic assignment is currently ambiguous. In these cases, the user is advised to manually analyse the full list of contacts using LPC software.
1. Carbon atoms belonging to a 4-, 5- or 6-member ring are 
   considered "aromatic" (Class V) if the ring is approximately
   planar, and "hydrophobic" (Class IV) or "neutral" (Classes
   VI, VII, VIII) if the ring is non-planar.
2. The oxygen atom of a carbonyl or hydroxy group is considered
   "hydroxy" (Class I) if the CO bond is longer than 1.29 Å, and
   "carbonyl" (Class II) if shorter.
3. All nitrogen atoms are considered "hydrophilic" (Class I).

Please E-mail any questions and/or suggestions concerning this page to Vladimir.Sobolev@weizmann.ac.il