Oligopeptide-binding protein from nontypeable Haemophilus influenzae has ligand-specific sites to accommodate peptides and heme in the binding pocket.

ABSTRACT: In nontypeable Haemophilus influenzae (NTHi), the oligopeptide-binding protein (OppA) serves as the substrate-binding protein (SBP) of the oligopeptide transport system responsible for the import of peptides. We solved the crystal structure of nthiOppA in complex with hydrophobic peptides of various sizes. Our novel hexapeptide complex demonstrates the flexibility of the nthiOppA-binding cavity to expand and accommodate the longer peptide while maintaining similar protein-peptide interactions of smaller peptide complexes. In addition to acquiring peptides from the host environment, as a heme auxotroph NTHi utilizes host hemoproteins as a source of essential iron. OppA is a member of the Cluster C SBP family, and unlike other SBP families, some members recognize two distinctly differ

SUBMITTER: Tanaka KJ 

PROVIDER: S-EPMC6341381 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature