Contacts of the helix formed by residues 72 - 85 (chain A) in PDB entry 1XAI


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 72 (chain A).
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     68A  GLU      4.9     3.6    -      -       -      +
     69A  LYS*     4.2    18.8    +      -       -      +
     70A  THR      2.8     7.9    +      -       -      +
     71A  LYS*     1.3    80.8    -      -       -      +
     73A  PHE*     1.3    63.5    +      -       -      +
     74A  GLU*     3.4    15.5    +      -       -      +
     75A  GLN*     3.2    22.9    +      -       -      +
     76A  TYR*     3.2    20.1    +      -       -      +
    139A  ILE*     3.9     8.3    -      -       -      +
    140A  ASN*     4.6     5.2    -      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with PHE 73 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     72A  THR*     1.3    70.5    -      -       -      +
     74A  GLU*     1.3    70.9    +      -       -      +
     76A  TYR*     3.0    21.7    +      +       -      +
     77A  GLN*     3.2     8.7    +      -       -      +
    139A  ILE*     3.9    17.6    -      -       +      +
    140A  ASN      4.3    10.5    +      -       -      -
    148A  ILE*     3.7    24.5    -      -       +      -
     76B  TYR*     3.9    17.7    -      +       -      -
     77B  GLN*     3.4    51.1    -      -       +      +
     80B  LEU*     3.7    39.7    -      -       +      -
     81B  GLU*     3.7    31.9    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with GLU 74 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     72A  THR*     3.4    13.7    -      -       -      +
     73A  PHE*     1.3    85.5    +      -       -      +
     75A  GLN*     1.3    62.0    +      -       -      +
     77A  GLN*     3.4     9.0    +      -       -      +
     78A  GLU*     3.3    20.2    +      -       -      +
    142A  LYS*     6.2     0.2    -      -       -      -
     77B  GLN*     3.6    27.1    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with GLN 75 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     63A  ILE      5.6     0.8    +      -       -      -
     64A  ILE*     4.7     3.4    -      -       -      +
     65A  PRO*     3.0    31.5    -      -       +      +
     69A  LYS      5.2     0.7    -      -       -      +
     70A  THR*     3.3    38.8    -      -       -      +
     72A  THR*     3.2    11.4    +      -       -      +
     74A  GLU*     1.3    77.2    -      -       -      +
     76A  TYR*     1.3    66.6    +      -       -      +
     78A  GLU*     3.2    32.8    +      -       -      +
     79A  THR*     2.6    49.1    +      -       -      -
    105A  PHE*     3.5     9.2    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with TYR 76 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     72A  THR      3.2    14.2    +      -       -      +
     73A  PHE*     3.0    18.3    +      +       -      +
     75A  GLN*     1.3    76.3    -      -       -      +
     77A  GLN*     1.3    62.3    +      -       -      +
     79A  THR*     4.2     1.0    -      -       -      -
     80A  LEU*     3.2    36.5    +      -       +      +
    105A  PHE*     3.7    13.1    -      +       +      -
    108A  PHE*     3.4    42.3    -      +       -      -
    109A  VAL*     4.2    12.9    -      -       +      +
    112A  THR*     2.5    41.1    +      -       -      +
    139A  ILE*     4.4     5.2    -      -       +      -
     73B  PHE*     3.8    23.6    -      +       -      -
     76B  TYR*     4.1    25.6    -      +       -      -
    108B  PHE*     3.5     5.7    -      +       -      -
    148B  ILE*     3.5     9.3    -      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with GLN 77 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     73A  PHE      3.2     7.8    +      -       -      +
     74A  GLU*     3.8     9.8    +      -       -      +
     75A  GLN      3.3     0.2    -      -       -      -
     76A  TYR*     1.3    76.6    -      -       -      +
     78A  GLU*     1.3    69.8    +      -       -      +
     80A  LEU*     3.1     2.6    +      -       -      +
     81A  GLU*     2.8    33.9    +      -       +      +
     73B  PHE*     3.4    55.6    -      -       +      +
     74B  GLU*     3.4    27.9    +      -       -      +
     77B  GLN*     5.9     2.6    -      -       -      +
    142B  LYS*     4.2    15.0    +      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with GLU 78 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     63A  ILE      5.7     0.9    -      -       -      +
     74A  GLU      3.3    11.0    +      -       -      +
     75A  GLN*     3.2    31.2    +      -       -      +
     77A  GLN*     1.3    81.2    -      -       -      +
     79A  THR*     1.3    53.8    +      -       -      +
     81A  GLU*     3.6     4.3    -      -       -      +
     82A  TYR*     2.7    42.3    +      -       +      +
----------------------------------------------------------
 Back to top of page

Residues in contact with THR 79 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     37A  LEU*     4.3    13.0    -      -       +      -
     62A  VAL*     4.3    15.2    -      -       +      +
     64A  ILE*     4.0     4.6    -      -       +      +
     75A  GLN*     2.6    37.7    +      -       -      +
     76A  TYR      4.2     0.9    -      -       -      -
     78A  GLU*     1.3    78.0    -      -       -      +
     80A  LEU*     1.3    58.8    +      -       -      +
     82A  TYR*     3.6     6.0    -      -       -      +
     83A  ILE*     2.9    43.4    +      -       +      +
    105A  PHE*     3.6    25.4    -      -       +      -
    109A  VAL*     4.5     7.6    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with LEU 80 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     76A  TYR*     3.2    47.4    +      -       +      +
     77A  GLN      3.1     4.7    +      -       -      +
     79A  THR*     1.3    74.7    -      -       -      +
     81A  GLU*     1.3    61.8    +      -       -      +
     83A  ILE*     3.0     6.0    +      -       +      +
     84A  LEU*     2.8    34.8    +      -       +      +
    109A  VAL*     3.6    33.9    -      -       +      +
    112A  THR*     4.0     0.9    -      -       -      +
    113A  LEU*     3.6    30.1    -      -       +      -
     73B  PHE*     3.6    25.6    -      -       +      -
    148B  ILE*     3.6    20.0    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with GLU 81 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     77A  GLN*     2.8    32.7    +      -       +      +
     78A  GLU*     3.7     4.0    -      -       -      +
     80A  LEU*     1.3    73.3    -      -       -      +
     82A  TYR*     1.3    65.2    +      -       -      +
     84A  LEU*     3.9     3.7    -      -       -      +
     85A  SER*     3.1    21.8    +      -       -      -
     73B  PHE*     3.6    27.8    -      -       +      -
    141B  SER*     2.6    30.4    +      -       -      -
    142B  LYS*     3.2    48.3    +      -       +      +
    143B  GLN*     4.7     3.3    -      -       -      +
----------------------------------------------------------
 Back to top of page

Residues in contact with TYR 82 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     35A  PHE*     5.3     0.7    -      +       -      -
     60A  HIS*     6.2     1.6    -      -       +      -
     61A  LYS      5.2     5.0    +      -       -      -
     62A  VAL*     4.6    17.3    -      -       +      -
     78A  GLU*     2.7    28.1    +      -       +      +
     79A  THR*     3.6     6.7    -      -       -      +
     81A  GLU*     1.3    72.9    -      -       -      +
     83A  ILE*     1.3    77.8    +      -       +      +
     85A  SER*     2.5    28.3    +      -       -      -
     86A  HIS*     3.0    36.5    +      +       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with ILE 83 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     35A  PHE*     3.7    27.1    -      -       +      -
     37A  LEU*     5.0     2.2    -      -       +      -
     62A  VAL*     3.7    30.5    -      -       +      -
     79A  THR*     2.9    32.1    +      -       +      +
     80A  LEU*     3.0    10.7    +      -       +      +
     82A  TYR*     1.3    84.8    -      -       +      +
     84A  LEU*     1.3    65.0    +      -       -      +
     86A  HIS*     2.9    27.6    +      -       -      +
     88A  VAL*     3.8    19.2    -      -       +      +
     94A  ILE*     5.0     7.6    -      -       +      -
    109A  VAL*     5.2     4.0    -      -       +      -
    113A  LEU*     3.9    26.2    -      -       +      -
----------------------------------------------------------
 Back to top of page

Residues in contact with LEU 84 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     80A  LEU      2.8    22.0    +      -       -      +
     81A  GLU*     3.9     5.2    -      -       -      +
     83A  ILE*     1.3    69.4    -      -       -      +
     85A  SER*     1.3    52.0    +      -       -      +
     86A  HIS      2.5    17.8    +      -       -      -
     87A  HIS*     2.8    19.8    +      -       -      -
     88A  VAL*     4.0    11.3    +      -       +      -
    113A  LEU*     3.7    24.9    -      -       +      -
    114A  LEU*     3.8    23.8    -      -       +      -
    141B  SER*     3.3    34.3    -      -       -      +
    143B  GLN*     3.9    18.6    -      -       +      +
    147B  LEU*     3.6    12.6    -      -       +      +
    148B  ILE*     3.5    21.8    -      -       +      -
    312B  SER*     5.1     1.0    +      -       -      -
----------------------------------------------------------
 Back to top of page

Residues in contact with SER 85 (chain A). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
     81A  GLU      3.1    11.6    +      -       -      -
     82A  TYR*     2.5    25.7    +      -       -      -
     83A  ILE      3.0     1.0    +      -       -      -
     84A  LEU*     1.3    73.0    -      -       -      +
     86A  HIS*     1.3    64.4    +      -       -      +
     87A  HIS*     3.5     8.5    +      -       -      -
    143B  GLN*     2.9    24.6    +      -       -      -
----------------------------------------------------------
 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