Intramolecular domain-domain association/dissociation and phosphoryl transfer in the mannitol transporter of Escherichia coli are not coupled.

ABSTRACT: The Escherichia coli mannitol transporter (II(Mtl)) comprises three domains connected by flexible linkers: a transmembrane domain (C) and two cytoplasmic domains (A and B). II(Mtl) catalyzes three successive phosphoryl-transfer reactions: one intermolecular (from histidine phosphocarrier protein to the A domain) and two intramolecular (from the A to the B domain and from the B domain to the incoming sugar bound to the C domain). A key functional requirement of II(Mtl) is that the A and B cytoplasmic domains be able to rapidly associate and dissociate while maintaining reasonably high occupancy of an active stereospecific AB complex to ensure effective phosphoryl transfer along the pathway. We have investigated the rate of intramolecular domain-domain association and dissociation in IIBA(Mt

SUBMITTER: Suh JY 

PROVIDER: S-EPMC1805604 | biostudies-literature | 2007 Feb

REPOSITORIES: biostudies-literature