Crystal structure of a prokaryotic homologue of the mammalian oligopeptide-proton symporters, PepT1 and PepT2.

ABSTRACT: PepT1 and PepT2 are major facilitator superfamily (MFS) transporters that utilize a proton gradient to drive the uptake of di- and tri-peptides in the small intestine and kidney, respectively. They are the major routes by which we absorb dietary nitrogen and many orally administered drugs. Here, we present the crystal structure of PepT(So), a functionally similar prokaryotic homologue of the mammalian peptide transporters from Shewanella oneidensis. This structure, refined using data up to 3.6 Å resolution, reveals a ligand-bound occluded state for the MFS and provides new insights into a general transport mechanism. We have located the peptide-binding site in a central hydrophilic cavity, which occludes a bound ligand from both sides of the membrane. Residues thought to be involved in pro

SUBMITTER: Newstead S 

PROVIDER: S-EPMC3025455 | biostudies-literature | 2011 Jan

REPOSITORIES: biostudies-literature