Structure, dynamics, and substrate-induced conformational changes of the multidrug transporter EmrE in liposomes.

ABSTRACT: EmrE, a member of the small multidrug transporters superfamily, extrudes positively charged hydrophobic compounds out of Escherichia coli cytoplasm in exchange for inward movement of protons down their electrochemical gradient. Although its transport mechanism has been thoroughly characterized, the structural basis of energy coupling and the conformational cycle mediating transport have yet to be elucidated. In this study, EmrE structure in liposomes and the substrate-induced conformational changes were investigated by systematic spin labeling and EPR analysis. Spin label mobilities and accessibilities describe a highly dynamic ligand-free (apo) conformation. Dipolar coupling between spin labels across the dimer reveals at least two spin label populations arising from different packing int

SUBMITTER: Amadi ST 

PROVIDER: S-EPMC2924113 | biostudies-literature | 2010 Aug

REPOSITORIES: biostudies-literature