2XUT: Crystal structure of a proton dependent oligopeptide (POT) family transporter

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 A 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 proton coupling have also been identified near the extracellular gate of the cavity. Based on these findings and associated kinetic data, we propose that PepT(So) represents a sound model system for understanding mammalian peptide transport as catalysed by PepT1 and PepT2.
PDB ID: 2XUTDownload
MMDB ID: 87292
PDB Deposition Date: 2010/10/21
Updated in MMDB: 2010/12
Experimental Method:
x-ray diffraction
Resolution: 3.62  Å
Source Organism:
Similar Structures:
Biological Unit for 2XUT: monomeric; determined by author and by software (PISA)
Molecular Components in 2XUT
Label Count Molecule
Protein (1 molecule)
Proton/peptide Symporter Family Protein
Molecule annotation
* Click molecule labels to explore molecular sequence information.

Citing MMDB