Contacts of the helix formed by residues 239 - 260 (chain M) in PDB entry 2I2X


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 ALA 239 (chain M).
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    179M  ASN*     5.8     0.2    +      -       -      -
    238M  LEU*     1.3    76.1    -      -       -      +
    240M  HIS*     1.3    60.3    +      -       -      +
    241M  THR*     3.9     5.8    -      -       -      +
    242M  ILE*     2.9    29.5    +      -       +      +
    243M  ALA*     3.1     9.9    +      -       -      +
    417M  PHE*     4.5    15.5    -      -       +      -
    418M  GLU*     5.2     4.9    -      -       -      -
    421M  ALA*     3.7    30.3    -      -       +      -
     94N  PHE*     3.4    16.4    -      -       -      -
     96N  PRO*     5.7     0.4    -      -       -      +
----------------------------------------------------------
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Residues in contact with HIS 240 (chain M). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    230M  GLY*     2.8    27.6    +      -       -      -
    231M  GLY      3.2    12.1    +      -       -      -
    232M  GLY      3.2    25.5    +      -       -      -
    233M  LEU*     4.2     9.4    +      -       +      -
    235M  ASN*     5.2     2.4    +      -       -      +
    238M  LEU      3.2    15.5    -      -       -      -
    239M  ALA*     1.3    68.0    -      -       -      +
    241M  THR*     1.3    64.7    +      -       -      +
    242M  ILE      3.0     1.8    -      -       -      -
    243M  ALA*     3.3     4.3    +      -       +      +
    244M  VAL*     3.1    25.8    +      -       -      +
    298M  VAL*     5.9     2.0    -      -       +      -
    364M  ASP*     2.6    37.4    +      -       -      +
    365M  PRO*     3.8     9.4    -      -       +      -
    366M  GLN*     3.4    18.8    +      -       -      +
    418M  GLU*     3.9    14.8    +      -       -      +
     15N  ARG*     4.4     3.2    +      -       -      -
     94N  PHE*     5.7     2.0    -      +       -      -
----------------------------------------------------------
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Residues in contact with THR 241 (chain M). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    239M  ALA*     3.9     1.7    -      -       -      +
    240M  HIS*     1.3    79.4    -      -       -      +
    242M  ILE*     1.3    58.1    +      -       -      +
    244M  VAL*     3.2    21.3    -      -       -      +
    245M  ILE*     3.4    18.5    -      -       -      +
    365M  PRO*     3.9    10.5    -      -       +      +
    404M  ILE*     4.2     9.6    -      -       +      -
    414M  LEU*     3.9    22.0    -      -       +      -
    418M  GLU*     2.9    43.0    +      -       +      +
    421M  ALA*     3.6    14.0    -      -       -      +
    422M  LEU*     3.8    21.0    -      -       +      +
----------------------------------------------------------
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Residues in contact with ILE 242 (chain M). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    176M  VAL*     5.9     1.3    -      -       +      -
    179M  ASN*     3.3    39.3    -      -       +      +
    181M  ILE*     4.0    25.6    -      -       +      -
    184M  LEU*     4.1    12.5    -      -       +      +
    226M  ALA*     6.4     0.2    -      -       +      -
    238M  LEU*     4.1    17.0    -      -       +      -
    239M  ALA*     2.9    20.1    +      -       +      +
    241M  THR*     1.3    77.4    +      -       -      +
    243M  ALA*     1.3    66.3    +      -       -      +
    244M  VAL      3.1     2.0    -      -       -      -
    245M  ILE*     3.1    17.0    +      -       +      +
    246M  ALA*     3.3    11.1    +      -       +      +
    421M  ALA*     4.1    30.1    -      -       +      +
    425M  ALA*     4.8     4.5    -      -       +      -
----------------------------------------------------------
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Residues in contact with ALA 243 (chain M). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    223M  ALA      5.1     2.4    -      -       -      +
    226M  ALA*     4.2    20.3    -      -       -      +
    227M  MET*     4.4     1.3    -      -       -      +
    230M  GLY*     5.4     0.7    -      -       -      -
    238M  LEU*     4.0    22.4    -      -       +      +
    239M  ALA      3.1     8.7    +      -       -      +
    240M  HIS*     3.6    10.5    -      -       +      +
    242M  ILE*     1.3    76.4    -      -       -      +
    244M  VAL*     1.3    60.8    +      -       -      +
    246M  ALA*     3.5     5.5    +      -       -      +
    247M  ARG*     3.2    19.2    +      -       -      +
    366M  GLN*     3.6    27.3    -      -       -      +
----------------------------------------------------------
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Residues in contact with VAL 244 (chain M). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    240M  HIS      3.1    15.2    +      -       -      +
    241M  THR*     3.2    24.7    -      -       -      +
    242M  ILE      3.1     0.2    -      -       -      -
    243M  ALA*     1.3    76.3    -      -       -      +
    245M  ILE*     1.3    62.5    +      -       +      +
    247M  ARG*     3.2     6.6    +      -       +      -
    248M  ALA      3.1    18.0    +      -       -      -
    365M  PRO*     3.4    30.7    -      -       +      +
    366M  GLN*     3.7    21.7    -      -       -      +
    369M  MET*     3.4    31.4    -      -       +      +
    400M  CYS*     3.7    12.8    -      -       -      -
    404M  ILE*     4.3     7.0    -      -       +      -
    422M  LEU*     5.7     0.7    -      -       +      -
----------------------------------------------------------
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Residues in contact with ILE 245 (chain M). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    181M  ILE*     4.5     9.9    -      -       +      -
    184M  LEU*     5.3     4.3    -      -       +      -
    241M  THR      3.4    19.1    -      -       -      +
    242M  ILE*     3.1    10.6    +      -       +      +
    244M  VAL*     1.3    74.3    -      -       +      +
    246M  ALA*     1.3    67.3    +      -       -      +
    248M  ALA*     3.1     3.9    +      -       -      +
    249M  ILE*     3.0    40.5    +      -       +      +
    397M  ALA*     4.1    14.6    -      -       +      +
    400M  CYS*     4.1    15.9    -      -       -      -
    401M  CYS*     3.7    25.4    -      -       -      -
    422M  LEU*     4.4     6.3    -      -       +      -
    425M  ALA*     3.6    30.5    -      -       +      -
    429M  LEU*     4.4     7.6    -      -       +      -
----------------------------------------------------------
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Residues in contact with ALA 246 (chain M). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    172M  PHE*     5.0     1.3    -      -       +      -
    184M  LEU*     4.6    13.2    -      -       +      +
    188M  ILE*     4.0    25.5    -      -       +      +
    223M  ALA*     4.1     7.3    -      -       -      +
    226M  ALA*     4.3    17.9    -      -       +      -
    242M  ILE*     3.3     8.6    +      -       +      +
    243M  ALA      3.5    10.5    -      -       -      +
    245M  ILE*     1.3    78.6    -      -       -      +
    247M  ARG*     1.3    57.0    +      -       -      +
    249M  ILE*     3.4     8.1    +      -       -      +
    250M  SER*     3.0    28.8    +      -       -      -
----------------------------------------------------------
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Residues in contact with ARG 247 (chain M). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    219M  ASP      5.3     1.2    +      -       -      -
    223M  ALA*     3.4    32.6    +      -       +      +
    224M  ASN*     2.6    32.3    +      -       -      -
    227M  MET*     3.8    21.0    -      -       -      +
    243M  ALA      3.2    10.5    +      -       -      +
    244M  VAL*     3.4    14.1    -      -       +      +
    245M  ILE      3.2     0.6    -      -       -      -
    246M  ALA*     1.3    76.2    -      -       -      +
    248M  ALA*     1.3    63.9    +      -       -      +
    250M  SER*     2.7    21.9    +      -       -      -
    251M  ALA*     3.3     5.5    +      -       -      +
    269M  CYS      4.2     0.4    +      -       -      -
    271M  TYR*     3.6    27.0    -      -       -      +
    272M  GLU*     3.0    44.3    +      -       +      +
    275M  ILE*     4.8     0.6    -      -       +      +
    299M  MET*     5.5     1.6    -      -       -      +
    366M  GLN*     5.6     1.3    +      -       +      +
    369M  MET*     3.9    13.0    -      -       +      -
    370M  LEU*     4.0    19.4    -      -       +      +
----------------------------------------------------------
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Residues in contact with ALA 248 (chain M). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    244M  VAL      3.1     6.6    +      -       -      +
    245M  ILE      3.1     8.2    +      -       -      +
    247M  ARG*     1.3    75.4    -      -       -      +
    249M  ILE*     1.3    62.7    +      -       -      +
    251M  ALA*     3.2     7.3    +      -       -      +
    252M  PRO*     3.1    17.8    -      -       -      +
    275M  ILE*     4.7     6.3    -      -       -      -
    369M  MET*     3.5    16.5    -      -       +      +
    378M  VAL*     4.7     3.9    -      -       +      +
    396M  ALA*     3.5    34.4    -      -       +      +
    397M  ALA*     4.5     1.1    -      -       -      -
    400M  CYS*     3.6    19.5    -      -       +      -
----------------------------------------------------------
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Residues in contact with ILE 249 (chain M). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    181M  ILE*     5.0     1.8    -      -       +      +
    184M  LEU*     4.2    11.7    -      -       +      +
    185M  LEU*     3.9    28.7    -      -       +      +
    188M  ILE*     3.8    11.6    -      -       +      +
    189M  GLY*     3.5    32.0    -      -       -      +
    245M  ILE*     3.0    33.4    +      -       +      +
    246M  ALA*     3.8     5.8    -      -       -      +
    247M  ARG      3.3     0.2    -      -       -      -
    248M  ALA*     1.3    76.3    -      -       -      +
    250M  SER*     1.3    58.4    +      -       -      +
    252M  PRO*     3.0    22.8    -      -       -      +
    253M  ARG*     3.7     5.5    +      -       -      +
    393M  ALA*     4.0    15.9    -      -       +      +
    397M  ALA*     3.7    21.8    -      -       +      -
    429M  LEU*     5.3     1.3    -      -       +      -
----------------------------------------------------------
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Residues in contact with SER 250 (chain M). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    188M  ILE*     3.6    10.3    -      -       -      +
    219M  ASP*     3.1    33.4    -      -       -      -
    223M  ALA*     3.8     4.3    -      -       -      +
    246M  ALA      3.0    13.9    +      -       -      -
    247M  ARG*     2.7    20.8    +      -       -      -
    249M  ILE*     1.3    74.8    -      -       -      +
    251M  ALA*     1.3    64.4    +      -       -      +
    253M  ARG*     3.3     2.8    +      -       -      +
    254M  SER*     2.9    29.6    +      -       -      -
    272M  GLU*     3.4    19.9    +      -       -      +
----------------------------------------------------------
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Residues in contact with ALA 251 (chain M). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    247M  ARG      3.3     1.2    +      -       -      +
    248M  ALA      3.2     9.3    +      -       -      +
    250M  SER*     1.3    83.0    +      -       -      +
    252M  PRO*     1.4    64.8    -      -       +      +
    254M  SER      3.3     0.9    +      -       -      -
    255M  LEU*     2.8    28.4    +      -       -      +
    272M  GLU*     3.9    12.6    -      -       +      +
    275M  ILE*     3.6    45.5    -      -       +      -
    276M  VAL*     3.8     7.3    -      -       +      +
    279M  ILE*     6.1     0.4    -      -       -      -
    382M  ILE*     4.0     4.7    -      -       +      -
----------------------------------------------------------
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Residues in contact with PRO 252 (chain M). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    189M  GLY      6.2     0.2    -      -       -      +
    193M  SER*     4.1     3.6    +      -       -      +
    248M  ALA      3.1    13.7    -      -       -      +
    249M  ILE      3.0    23.6    -      -       -      +
    251M  ALA*     1.4    80.9    -      -       +      +
    253M  ARG*     1.3    64.0    +      -       -      +
    255M  LEU*     3.5    12.8    -      -       +      +
    256M  VAL*     3.4     2.9    -      -       -      +
    382M  ILE*     3.8    20.8    -      -       +      -
    389M  ILE      5.5     0.4    -      -       -      +
    392M  ARG*     2.9    52.2    +      -       +      +
    393M  ALA*     3.7    28.5    -      -       +      +
    396M  ALA*     4.4     0.2    -      -       +      -
----------------------------------------------------------
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Residues in contact with ARG 253 (chain M). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    165M  SER*     2.9    28.5    +      -       -      -
    167M  GLY      5.6     2.8    +      -       -      +
    188M  ILE*     3.5    29.4    -      -       +      +
    189M  GLY*     4.9     0.6    -      -       -      -
    192M  GLY*     4.0    17.4    -      -       -      -
    193M  SER*     3.6    11.8    +      -       -      +
    196M  MET*     3.4    21.7    -      -       +      +
    217M  ASP*     2.9    28.1    +      -       -      +
    218M  THR      3.0    36.2    +      -       -      +
    219M  ASP*     3.2    26.3    +      -       -      +
    222M  GLN*     4.4     2.0    +      -       -      +
    249M  ILE      3.7     5.6    +      -       -      +
    250M  SER      3.3     9.8    +      -       -      +
    251M  ALA      3.2     0.8    -      -       -      -
    252M  PRO*     1.3    78.1    -      -       -      +
    254M  SER*     1.3    74.7    +      -       -      +
    256M  VAL*     3.1    23.6    +      -       -      +
----------------------------------------------------------
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Residues in contact with SER 254 (chain M). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    196M  MET*     4.0     2.6    -      -       -      +
    217M  ASP*     5.4     4.8    -      -       -      +
    218M  THR*     5.2     2.7    -      -       -      -
    219M  ASP      3.6     0.6    +      -       -      -
    250M  SER      2.9    13.8    +      -       -      -
    251M  ALA      4.0     2.7    -      -       -      -
    253M  ARG*     1.3    97.5    +      -       -      +
    255M  LEU*     1.3    65.4    +      -       -      +
    256M  VAL      3.0     2.8    +      -       -      -
    257M  ALA*     3.4     9.6    +      -       -      +
    258M  TYR*     3.3    24.2    -      -       -      -
    272M  GLU*     2.8    33.2    +      -       -      -
    273M  ASN*     5.2     3.4    -      -       -      -
    276M  VAL*     4.5     5.6    -      -       -      -
----------------------------------------------------------
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Residues in contact with LEU 255 (chain M). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
      6M  TYR*     3.8    11.0    -      -       +      +
    251M  ALA      2.8    17.4    +      -       -      +
    252M  PRO*     3.5     8.1    -      -       +      +
    253M  ARG      3.2     0.4    -      -       -      -
    254M  SER*     1.3    77.8    -      -       -      +
    256M  VAL*     1.3    62.3    +      -       -      +
    257M  ALA      3.3     0.2    -      -       -      -
    258M  TYR*     3.1    12.1    +      -       -      +
    259M  GLU*     3.1    39.2    +      -       -      +
    276M  VAL*     4.1     9.6    -      -       +      +
    279M  ILE*     3.8    26.7    -      -       +      -
    280M  THR*     3.3    33.9    -      -       +      -
    382M  ILE*     4.1    20.6    -      -       +      -
    392M  ARG*     3.9    14.1    -      -       -      +
----------------------------------------------------------
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Residues in contact with VAL 256 (chain M). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
      5M  ARG*     3.7    17.7    -      -       -      +
    193M  SER*     3.6    21.8    -      -       -      +
    196M  MET*     3.5     9.2    -      -       +      -
    197M  GLU*     3.3    36.6    -      -       +      +
    252M  PRO      3.4     2.9    -      -       -      +
    253M  ARG      3.2    16.6    -      -       -      +
    254M  SER      3.0     1.0    -      -       -      -
    255M  LEU*     1.3    78.0    -      -       -      +
    257M  ALA*     1.3    61.9    +      -       -      +
    259M  GLU*     3.1    11.0    +      -       -      +
    260M  ALA*     3.0    22.4    +      -       +      +
    392M  ARG*     3.3    23.3    -      -       -      +
----------------------------------------------------------
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Residues in contact with ALA 257 (chain M). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    196M  MET*     3.5    22.7    -      -       +      +
    200M  TRP*     3.5    37.2    -      -       +      +
    217M  ASP*     4.5     7.9    -      -       +      +
    254M  SER      3.4     8.3    +      -       -      +
    255M  LEU      3.3     0.6    -      -       -      -
    256M  VAL*     1.3    76.5    -      -       -      +
    258M  TYR*     1.3    62.6    +      -       +      +
    260M  ALA*     3.2     4.5    +      -       -      +
    261M  GLY      3.2     9.9    +      -       -      -
    262M  ALA*     3.0    30.1    +      -       +      +
----------------------------------------------------------
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Residues in contact with TYR 258 (chain M). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
      6M  TYR*     4.3     9.8    +      -       +      -
    215M  ALA      3.3    20.9    -      -       -      -
    216M  GLY*     3.7    10.9    -      -       -      -
    217M  ASP      4.0     5.3    +      -       -      -
    254M  SER*     3.3    26.2    -      -       -      -
    255M  LEU      3.1     6.9    +      -       -      +
    256M  VAL      3.1     0.4    -      -       -      -
    257M  ALA*     1.3    75.3    -      -       +      +
    259M  GLU*     1.3    64.3    +      -       -      +
    260M  ALA      3.1     2.1    +      -       -      -
    261M  GLY*     3.4     8.3    +      -       -      -
    262M  ALA*     3.4    31.5    -      -       +      +
    264M  GLY*     3.8     6.5    -      -       -      -
    266M  GLY*     3.0    28.6    -      -       -      -
    273M  ASN*     4.4     4.9    +      -       -      -
    276M  VAL*     3.5    27.6    -      -       +      -
    280M  THR*     4.1    11.7    -      -       +      -
    282M  MET*     3.9    22.4    -      -       -      +
    284M  MET*     3.7    15.8    -      -       +      -
----------------------------------------------------------
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Residues in contact with GLU 259 (chain M). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
      3M  ALA*     4.0     8.8    -      -       -      +
      4M  LYS*     3.1    48.9    +      -       -      +
      5M  ARG*     3.2    16.8    +      -       -      -
      6M  TYR*     3.0    35.4    +      -       +      -
    255M  LEU*     3.1    18.4    +      -       -      +
    256M  VAL*     3.1    15.3    +      -       -      +
    258M  TYR*     1.3    77.1    -      -       -      +
    260M  ALA*     1.3    58.3    +      -       -      +
    261M  GLY      3.5     0.6    +      -       -      -
    392M  ARG*     2.5    48.0    +      -       -      -
----------------------------------------------------------
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Residues in contact with ALA 260 (chain M). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
      3M  ALA*     4.2    19.7    -      -       +      +
    197M  GLU*     4.5     9.2    -      -       -      +
    200M  TRP*     3.3    13.0    -      -       +      +
    201M  THR*     4.0    28.9    -      -       -      +
    204M  SER*     3.1    14.3    +      -       -      -
    256M  VAL      3.0    15.8    +      -       -      +
    257M  ALA      3.4     6.7    -      -       -      +
    258M  TYR      3.1     0.2    -      -       -      -
    259M  GLU*     1.3    78.6    -      -       -      +
    261M  GLY*     1.3    54.7    +      -       -      +
----------------------------------------------------------
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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