Contacts of ligand ACE 1E in PDB entry 3GJQ

Ligand-Protein Contacts (LPC) are derived with the LPC 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.


On this page you will find:

Table II
Residues in contact with ligand ACE 1E in PDB entry 3GJQ
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Legend:
Dist - nearest distance (Å) between atoms of the ligand and the residue
Surf - contact surface area (Å2) between the ligand and the residue
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 contacting ligand by their side chain
       (including CA atoms)

----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue      Dist    Surf    HB    Arom    Phob    DC
----------------------------------------------------------
    206B  TRP*     5.0     2.0    -      -       +      -
    207B  ARG      4.1     7.6    -      -       -      +
    208B  ASN*     4.4    15.0    -      -       -      +
    214B  TRP*     3.7    39.7    -      -       +      +
    248B  GLU      4.9     1.8    -      -       -      +
    249B  SER*     3.7    10.3    -      -       -      -
    250B  PHE*     3.0    33.0    +      -       +      +
      2E  TRP*     1.3    65.2    +      -       +      +
      3E  GLU      3.9     2.2    -      -       -      +
----------------------------------------------------------


Table III
List of putative hydrogen bonds between ligand ACE 1E and protein in PDB entry 3GJQ
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Legend:
N     - ligand atom number in PDB entry
Dist  - distance (Å) between the ligand and protein atoms
Surf  - contact surface area (Å2) between the ligand and protein atoms
------------------------------------------------------------------------
    Ligand atom            Protein atom
-----------------   ----------------------------    Dist     Surf
  N   Name   Class    Residue       Name   Class
------------------------------------------------------------------------
  2   O      II       TRP    2E     N      III       2.3      0.3
  2   O      II       PHE  250B     N      III       3.0     25.8
------------------------------------------------------------------------


Table IV
Full list of atomic contacts with ligand ACE 1E in PDB entry 3GJQ
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Total number of contacts is 36
Legend:
N     - ligand atom number in PDB entry
Dist  - distance (A) between the ligand and protein atoms
Surf  - contact surface area (A**2) between the ligand and protein atoms
*     - indicates destabilizing contacts
------------------------------------------------------------------------
    Ligand atom            Protein atom
-----------------   ----------------------------    Dist     Surf
  N   Name   Class    Residue       Name   Class
------------------------------------------------------------------------
  1   C     VIII     TRP    2E     N      III       1.3      42.6  
  1   C     VIII     TRP    2E     CA     VII       2.4       2.9  
  1   C     VIII     TRP    2E     C      VI        3.4       1.8  
  1   C     VIII     GLU    3E     N      III       3.9       0.2  
  1   C     VIII     TRP    2E     CG      V        4.0       3.6  
  1   C     VIII     PHE  250B     O      II        4.0       0.4* 
  1   C     VIII     PHE  250B     N      III       4.1       0.7  
  1   C     VIII     ARG  207B     O      II        4.2       0.4* 
  1   C     VIII     TRP    2E     CD1     V        4.3       0.4  
  1   C     VIII     SER  249B     CA     VII       4.5       0.4  
  1   C     VIII     SER  249B     CB     VI        4.7       0.9  
  1   C     VIII     GLU    3E     O      II        4.9       2.0* 
  1   C     VIII     PHE  250B     CA     VII       4.9       0.2  
  1   C     VIII     TRP  206B     CE3     V        5.0       1.1  
  1   C     VIII     PHE  250B     CB     IV        5.0       1.6  
  2   O      II      TRP    2E     N      III       2.3       0.3  
  2   O      II      TRP    2E     CA     VII       2.8       6.9  
  2   O      II      PHE  250B     N      III       3.0      25.8  
  2   O      II      PHE  250B     O      II        3.1       2.9* 
  2   O      II      TRP    2E     C      VI        3.6       1.0  
  2   O      II      SER  249B     CA     VII       3.7       2.8  
  2   O      II      SER  249B     CB     VI        3.8       3.5  
  2   O      II      TRP    2E     O      II        3.9       0.2* 
  3   CH3    IV      TRP    2E     N      III       2.4       5.2* 
  3   CH3    IV      TRP  214B     NE1    III       3.7      26.7* 
  3   CH3    IV      TRP  214B     CZ2     V        3.7      12.8  
  3   CH3    IV      TRP  214B     CE2     V        4.1       0.2  
  3   CH3    IV      ARG  207B     O      II        4.1       7.2* 
  3   CH3    IV      ASN  208B     ND2    III       4.4      14.8* 
  3   CH3    IV      ASN  208B     CA     VII       4.5       0.2  
  3   CH3    IV      SER  249B     CA     VII       4.5       2.7  
  3   CH3    IV      PHE  250B     N      III       4.7       0.4* 
  3   CH3    IV      TRP    2E     CD1     V        4.9       0.2  
  3   CH3    IV      GLU  248B     O      II        4.9       1.8* 
  3   CH3    IV      TRP  206B     CB     IV        5.2       0.9  
  3   CH3    IV      PHE  250B     CB     IV        5.6       0.9  
------------------------------------------------------------------------


Table V
Complementarity values for the ligand ACE 1E in PDB entry 3GJQ
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---------------------------------------------
Theoretical maximum (Å2)                 179
Actual value (Å2)                         52
Normalised complementarity              0.29
---------------------------------------------


Table VI
Normalised complementarity as a function of atomic substitution for ligand ACE 1E in PDB entry 3GJQ
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Legend:
N- ligand atom number in PDB entry
Bold - indicates atomic substitution which could stabilize the complex
Italics- indicates atomic substitution which could destabilize the complex
Ligand atomAtom class
NTypeClassI IIIIIIVV VIVIIVIII
1 C VIII 0.31 0.28 -0.22 -0.19 0.33 0.33 -0.20 0.29
2 O II 0.33 0.29 -0.07 0.00 0.33 0.33 -0.07 0.29
3 CH3 IV 0.90 0.80 0.34 0.29 0.92 0.92 0.36 0.82


A short description of the analytical approach (back to top of page)

The analysis of ligand-protein contacts used in this page is based upon the surface complementarity approach developed in: Sobolev V., Wade R.C., Vriend G. and Edelman M. PROTEINS (1996) 25, 120-129.
The complementarity function therein is defined as:

CF=Sl-Si-E

Where Sl is the sum of all surface areas of legitimate atomic contacts between ligand and receptor, Si is the sum of all surface areas of illegitimate atomic contacts, and E is a repulsion term.

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 ligands are automatically assigned based on the atomic coordinates. However, in three cases the automatic assignment is currently ambiguous (due to low resolution). In these three cases, the user is advised to manually analyze the full list of contacts (Table IV).
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).

IN YOUR STRUCTURE, the following atoms fall in these ambiguous cases:
Ligand ACE    1
2. Oxygen ("hydroxy" or "carbonyl")
                     2 O  
Ligand ACE    6
2. Oxygen ("hydroxy" or "carbonyl")
                     2 O  


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