Contacts of ligand CA 301A in PDB entry 4M3C

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 CA 301A in PDB entry 4M3C
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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
----------------------------------------------------------
     88A  ASP*     4.5     4.3    -      -       -      -
    106A  GLY*     4.7     5.9    -      -       -      -
    108A  LEU*     5.8     0.3    -      -       -      -
    128A  ASP*     2.3    37.2    -      -       -      -
    130A  TYR      2.4     9.0    -      -       -      -
    132A  ASN*     2.1    39.0    -      -       -      -
    135A  PHE*     4.9     0.3    -      -       -      -
    137A  ASP*     2.4     9.4    -      -       -      -
----------------------------------------------------------


Table III
List of putative hydrogen bonds between ligand CA 301A and protein in PDB entry 4M3C
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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
------------------------------------------------------------------------
------------------------------------------------------------------------


Table IV
Full list of atomic contacts with ligand CA 301A in PDB entry 4M3C
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Total number of contacts is 12
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  CA      VI      ASN  132A     ND2    III       2.1      39.0  
  1  CA      VI      ASP  128A     OD2    II        2.3      31.5  
  1  CA      VI      TYR  130A     O      II        2.4       9.0  
  1  CA      VI      ASP  137A     OD2    II        2.4       9.4  
  1  CA      VI      ASP  128A     OD1    II        2.6       5.2  
  1  CA      VI      ASP  128A     CG     VI        2.8       0.5  
  1  CA      VI      ASP   88A     O      II        4.5       3.3  
  1  CA      VI      ASP   88A     OD2    II        4.7       1.0  
  1  CA      VI      GLY  106A     CA     VI        4.7       3.5  
  1  CA      VI      GLY  106A     O      II        4.7       2.4  
  1  CA      VI      PHE  135A     CD2     V        4.9       0.3  
  1  CA      VI      LEU  108A     CD1    IV        5.8       0.3  
------------------------------------------------------------------------


Table V
Complementarity values for the ligand CA 301A in PDB entry 4M3C
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---------------------------------------------
Theoretical maximum (Å2)                 105
Actual value (Å2)                        105
Normalised complementarity              1.00
---------------------------------------------


Table VI
Normalised complementarity as a function of atomic substitution for ligand CA 301A in PDB entry 4M3C
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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
1CA VI 0.99 -0.18 0.25 -0.91 1.00 1.00 0.26 -0.17


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  MN  302
3. Nitrogen ("hydrophilic")
                     1 N  
Ligand ABU  303
2. Oxygen ("hydroxy" or "carbonyl")
                     6 O      7 OXT
3. Nitrogen ("hydrophilic")
                     1 N  
Ligand  MN  302
3. Nitrogen ("hydrophilic")
                     1 N  
Ligand ABU  303
2. Oxygen ("hydroxy" or "carbonyl")
                     6 O      7 OXT
3. Nitrogen ("hydrophilic")
                     1 N  
Ligand  MN  302
3. Nitrogen ("hydrophilic")
                     1 N  
Ligand ABU  303
2. Oxygen ("hydroxy" or "carbonyl")
                     6 O      7 OXT
3. Nitrogen ("hydrophilic")
                     1 N  
Ligand GOL  304
2. Oxygen ("hydroxy" or "carbonyl")
                     2 O1     4 O2     6 O3 
Ligand  MN  302
3. Nitrogen ("hydrophilic")
                     1 N  
Ligand ABU  303
2. Oxygen ("hydroxy" or "carbonyl")
                     6 O      7 OXT
3. Nitrogen ("hydrophilic")
                     1 N  
Ligand GOL  304
2. Oxygen ("hydroxy" or "carbonyl")
                     2 O1     4 O2     6 O3 
Ligand  MN  302
3. Nitrogen ("hydrophilic")
                     1 N  
Ligand ABU  303
2. Oxygen ("hydroxy" or "carbonyl")
                     6 O      7 OXT
3. Nitrogen ("hydrophilic")
                     1 N  
Ligand  MN  302
3. Nitrogen ("hydrophilic")
                     1 N  
Ligand GOL  303
2. Oxygen ("hydroxy" or "carbonyl")
                     2 O1     4 O2     6 O3 
Ligand  MN  302
3. Nitrogen ("hydrophilic")
                     1 N  
Ligand  MN  302
3. Nitrogen ("hydrophilic")
                     1 N  
Ligand ABU  303
2. Oxygen ("hydroxy" or "carbonyl")
                     6 O      7 OXT
3. Nitrogen ("hydrophilic")
                     1 N  


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