1olc | pdb_00001olc
OLIGO-PEPTIDE BINDING PROTEIN (OPPA) COMPLEXED WITH LYS-LYS-LYS-ALA
Structural highlights
Function[OPPA_SALTY] This protein is a component of the oligopeptide permease, a binding protein-dependent transport system, it binds peptides up to five amino acids long with high affinity. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedBACKGROUND: 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. The crystal structures of the oligopeptide-binding protein OppA complexed with tripeptide and tetrapeptide ligands.,Tame JR, Dodson EJ, Murshudov G, Higgins CF, Wilkinson AJ Structure. 1995 Dec 15;3(12):1395-406. PMID:8747465[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References | ||||||||||||||||||
