A Loose Relationship: Incomplete H+/Sugar Coupling in the MFS Sugar Transporter GlcP.

ABSTRACT: The glucose transporter from Staphylococcus epidermidis, GlcPSe, is a homolog of the human GLUT sugar transporters of the major facilitator superfamily. Together with the xylose transporter from Escherichia coli, XylEEc, the other prominent prokaryotic GLUT homolog, GlcPSe, is equipped with a conserved proton-binding site arguing for an electrogenic transport mode. However, the electrophysiological analysis of GlcPSe presented here reveals important differences between the two GLUT homologs. GlcPSe, unlike XylEEc, does not perform steady-state electrogenic transport at symmetrical pH conditions. Furthermore, when a pH gradient is applied, partially uncoupled transport modes can be generated. In contrast to other bacterial sugar transporters analyzed so far, in GlcPSe sugar binding, translo

SUBMITTER: Bazzone A 

PROVIDER: S-EPMC5770559 | biostudies-literature | 2017 Dec

REPOSITORIES: biostudies-literature