Protonation-dependent conformational dynamics of the multidrug transporter EmrE.

ABSTRACT: The small multidrug transporter from Escherichia coli, EmrE, couples the energetically uphill extrusion of hydrophobic cations out of the cell to the transport of two protons down their electrochemical gradient. Although principal mechanistic elements of proton/substrate antiport have been described, the structural record is limited to the conformation of the substrate-bound state, which has been shown to undergo isoenergetic alternating access. A central but missing link in the structure/mechanism relationship is a description of the proton-bound state, which is an obligatory intermediate in the transport cycle. Here we report a systematic spin labeling and double electron electron resonance (DEER) study that uncovers the conformational changes of EmrE subsequent to protonation of critica

SUBMITTER: Dastvan R 

PROVIDER: S-EPMC4747756 | biostudies-literature | 2016 Feb

REPOSITORIES: biostudies-literature