Mapping daunorubicin-binding Sites in the ATP-binding cassette transporter MsbA using site-specific quenching by spin labels.

ABSTRACT: ATP-binding cassette (ABC) transporters transduce the free energy of ATP hydrolysis to power the mechanical work of substrate translocation across cell membranes. MsbA is an ABC transporter implicated in trafficking lipid A across the inner membrane of Escherichia coli. It has sequence similarity and overlapping substrate specificity with multidrug ABC transporters that export cytotoxic molecules in humans and prokaryotes. Despite rapid advances in structure determination of ABC efflux transporters, little is known regarding the location of substrate-binding sites in the transmembrane segment and the translocation pathway across the membrane. In this study, we have mapped residues proximal to the daunorubicin (DNR)-binding site in MsbA using site-specific, ATP-dependent quenching of DNR in

SUBMITTER: Smriti 

PROVIDER: S-EPMC2679490 | biostudies-literature | 2009 May

REPOSITORIES: biostudies-literature