PDBsum entry 1olc

Complex (binding protein/peptide)

PDB id: 1olc

Contents

Protein chain

517 a.a. *

Ligands

LYS-LYS-LYS-ALA

IUM ×8

Waters ×337

* Residue conservation analysis

PDB id:

1olc

Name:

Complex (binding protein/peptide)

Title:

Oligo-peptide binding protein (oppa) complexed with lys-lys-lys-ala

Structure:

Oligo-peptide binding protein. Chain: a. Synonym: oppa. Lys-lys-lys-ala. Chain: b. Engineered: yes. Other_details: co-crystallized with uranium acetate

Source:

Salmonella typhimurium. Organism_taxid: 602.

Biol. unit:

Dimer (from PQS)

Resolution:

2.10Å R-factor: 0.143 R-free: 0.197

Authors:

J.Tame,A.J.Wilkinson

Key ref:

J.R.Tame et al. (1995). The crystal structures of the oligopeptide-binding protein OppA complexed with tripeptide and tetrapeptide ligands. Structure, 3, 1395-1406. PubMed id: 8747465 DOI: 10.1016/S0969-2126(01)00276-3

Date:

10-Sep-95 Release date: 29-Jan-96

Protein chain

P06202  (OPPA_SALTY) -  Periplasmic oligopeptide-binding protein OppA from Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720)

Seq: 543 a.a.

Struc: 517 a.a.

DOI no: 10.1016/S0969-2126(01)00276-3

Structure 3:1395-1406 (1995)

PubMed id: 8747465

The crystal structures of the oligopeptide-binding protein OppA complexed with tripeptide and tetrapeptide ligands.

J.R.Tame, E.J.Dodson, G.Murshudov, C.F.Higgins, A.J.Wilkinson.

ABSTRACT

BACKGROUND: The periplasmic oligopeptide-binding protein OppA has a remarkably broad substrate specificity, binding peptides of two or five amino-acid residues with high affinity, but little regard to sequence. It is therefore an ideal system for studying how different chemical groups can be accommodated in a protein interior. The ability of the protein to bind peptides of different lengths has been studied by co-crystallising it with different ligands. RESULTS: Crystals of OppA from Salmonella typhimurium complexed with the peptides Lys-Lys-Lys (KKK) and Lys-Lys-Lys-Ala (KKKA) have been grown in the presence of uranyl ions which form important crystal contacts. These structures have been refined to 1.4 A and 2.1 A, respectively. The ligands are completely enclosed, their side chains pointing into large hydrated cavities and making few strong interactions with the protein. CONCLUSIONS: Tight peptide binding by OppA arises from strong hydrogen bonding and electrostatic interactions between the protein and the main chain of the ligand. Different basic side chains on the protein form salt bridges with the C terminus of peptide ligands of different lengths.

Selected figure(s)

Figure 1.
Figure 1. Stereo Cα trace of OppA in the closed, ligand bound form. The tri-lysine ligand is shown in thicker lines. Figure 1. Stereo Cα trace of OppA in the closed, ligand bound form. The tri-lysine ligand is shown in thicker lines.

Figure 5.
Figure 5. . Schematic diagram illustrating the interactions made by the main chain of the tri-lysine ligand with OppA. Protein residues are labelled. Hydrogen bonding and electrostatic interactions are indicated by the dotted lines. R1, R2 and R3 indicate the ligand side chains. Figure 5. . Schematic diagram illustrating the interactions made by the main chain of the tri-lysine ligand with OppA. Protein residues are labelled. Hydrogen bonding and electrostatic interactions are indicated by the dotted lines. R1, R2 and R3 indicate the ligand side chains.

The above figures are reprinted by permission from Cell Press: Structure (1995, 3, 1395-1406) copyright 1995.

Figures were selected by an automated process.