A salt-bridge motif involved in ligand binding and large-scale domain motions of the maltose-binding protein.

ABSTRACT: The uptake of nutrients is essential for the survival of bacterial cells. Many specialized systems have evolved, such as the maltose-dependent ABC transport system that transfers oligosaccharides through the cytoplasmic membrane. The maltose/maltodextrin-binding protein (MBP) serves as an initial high-affinity binding component in the periplasm that delivers the bound sugar into the cognate ABC transporter MalFGK(2). We have investigated the domain motions induced by the binding of the ligand maltotriose into the binding cleft using molecular dynamics simulations. We find that MBP is predominantly in the open state without ligand and in the closed state with ligand bound. Oligosaccharide binding induces a closure motion (30.0 degrees rotation), whereas ligand removal leads to domain openin

SUBMITTER: Stockner T 

PROVIDER: S-EPMC1366833 | biostudies-literature | 2005 Nov

REPOSITORIES: biostudies-literature