Contacts of ligand SO4 505E in PDB entry 3ECS
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.
(In PDB entry 3ECS some ATOMs are from nucleic
acids or have "unusual" 3-letter residue code. The
analysis does not take into account these atoms.)
On this page you will find:
- 3D ligand structure presentation with
Jmol, an open-source
Java viewer for chemical structures in 3D (top left window)
- Solvent accessible surface of the ligand
complexed with protein and in uncomplexed form
(top right window). Clicking
on "select" buttons highlights atoms in 3D picture
- List of residues in contact
with the ligand
- List of putative hydrogen
bonds formed by the ligand
- Full list of atomic contacts
formed by the ligand
- Values of ligand complementarity
(a function of atomic contact
surface area and the chemical properties of contacting atoms)
- Prediction of complementarity changes as a
function of atomic substitution
in the
ligand
Table II
Residues in contact with ligand SO4 505E
in PDB entry 3ECS (back to top of page)
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
----------------------------------------------------------
21E ALA* 4.7 3.5 - - - +
130E TYR* 4.7 2.8 + - - -
131E SER* 2.8 31.9 + - - -
132E ARG* 2.7 62.7 + - - +
133E VAL* 3.2 26.2 + - - +
196E GLY* 4.6 6.1 - - - -
197E ALA 4.6 2.9 + - - -
198E GLU* 5.4 6.6 - - - +
231E GLU* 3.6 5.9 + - - -
234E LYS* 3.0 28.4 + - - -
----------------------------------------------------------
Table III
List of putative hydrogen bonds between ligand SO4 505E
and protein in PDB entry 3ECS
(back to top
of page)
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 O1 I LYS 234E NZ III 3.0 14.4
2 O1 I ARG 132E NH2 III 3.6 10.4
2 O1 I ALA 197E O II 4.6 1.2
3 O2 I ARG 132E NE III 2.7 24.3
3 O2 I ARG 132E N III 3.0 12.5
3 O2 I ARG 132E NH2 III 3.1 3.6
3 O2 I TYR 130E O II 4.9 1.0
4 O3 I LYS 234E NZ III 3.3 6.1
4 O3 I GLU 231E OE2 II 3.6 5.9
4 O3 I ARG 132E NE III 3.9 2.3
5 O4 I SER 131E OG I 2.8 25.5
5 O4 I LYS 234E NZ III 3.9 4.3
5 O4 I VAL 133E N III 4.0 0.3
5 O4 I TYR 130E O II 4.7 0.7
5 O4 I ALA 197E N III 4.9 0.9
------------------------------------------------------------------------
Table IV
Full list of atomic contacts with ligand SO4 505E
in PDB entry 3ECS (back
to top of page)
Total number of contacts is 35
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 S VI LYS 234E NZ III 3.6 1.6
1 S VI ARG 132E N III 3.7 1.6
1 S VI ARG 132E NE III 3.8 1.3
1 S VI TYR 130E O II 5.4 0.2
2 O1 I LYS 234E NZ III 3.0 14.4
2 O1 I ARG 132E NH2 III 3.6 10.4
2 O1 I LYS 234E CE VII 4.0 2.1
2 O1 I ALA 197E O II 4.6 1.2
2 O1 I ALA 197E C VI 5.3 0.7
2 O1 I GLU 198E CG IV 5.4 6.6*
2 O1 I ALA 21E CB IV 5.4 0.7*
3 O2 I ARG 132E NE III 2.7 24.3
3 O2 I ARG 132E N III 3.0 12.5
3 O2 I ARG 132E NH2 III 3.1 3.6
3 O2 I ARG 132E CZ VI 3.2 0.7
3 O2 I ARG 132E CG IV 3.4 0.2*
3 O2 I SER 131E CA VII 4.0 1.9
3 O2 I TYR 130E O II 4.9 1.0
3 O2 I TYR 130E CD2 V 5.3 0.9
4 O3 I VAL 133E CG2 IV 3.2 24.3*
4 O3 I LYS 234E NZ III 3.3 6.1
4 O3 I GLU 231E OE2 II 3.6 5.9
4 O3 I ARG 132E CB IV 3.8 5.9*
4 O3 I ARG 132E NE III 3.9 2.3
4 O3 I ALA 21E CB IV 4.7 2.8*
5 O4 I SER 131E OG I 2.8 25.5
5 O4 I SER 131E CB VI 3.5 3.6
5 O4 I SER 131E CA VII 3.5 0.9
5 O4 I LYS 234E NZ III 3.9 4.3
5 O4 I VAL 133E N III 4.0 0.3
5 O4 I VAL 133E CG2 IV 4.2 1.6*
5 O4 I GLY 196E CA VI 4.6 6.1
5 O4 I TYR 130E O II 4.7 0.7
5 O4 I ALA 197E N III 4.9 0.9
5 O4 I ALA 197E C VI 5.6 0.2
------------------------------------------------------------------------
Table V
Complementarity values for the ligand SO4 505E
in PDB entry 3ECS (back to top of page)
---------------------------------------------
Theoretical maximum (Å2) 195
Actual value (Å2) 93
Normalised complementarity 0.48
---------------------------------------------
Table VI
Normalised complementarity as a function of atomic
substitution for ligand SO4 505E
in PDB entry 3ECS (back
to top of page)
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 atom | Atom class |
|---|
| N | Type | Class | I
| II | III | IV | V |
VI | VII | VIII |
|---|
| 1 | S
| VI |
0.48 |
0.47
|
0.43 |
0.43
|
0.48 |
0.48
|
0.43 |
0.47
|
| 2 | O1
| I |
0.48 |
0.46
|
0.20 |
0.28
|
0.55 |
0.55
|
0.28 |
0.54
|
| 3 | O2
| I |
0.48 |
0.47
|
0.04 |
0.05
|
0.48 |
0.48
|
0.05 |
0.47
|
| 4 | O3
| I |
0.48 |
0.42
|
0.39 |
0.67
|
0.81 |
0.81
|
0.73 |
0.75
|
| 5 | O4
| I |
0.48 |
0.47
|
0.41 |
0.17
|
0.49 |
0.49
|
0.43 |
0.48
|
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:
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:
NONE.
Please E-mail any questions and/or suggestions
concerning this page to
Vladimir.Sobolev@weizmann.ac.il