4APS

Crystal structure of a POT family peptide transporter in an inward open conformation.

Summary for 4APS

• Entry DOI: 10.2210/pdb4aps/pdb
• Descriptor: DI-OR TRIPEPTIDE H+ SYMPORTER, CADMIUM ION (2 entities in total)
• Functional Keywords: transport protein, peptide transport, major facilitator superfamily, transporter, mfs
• Biological source: STREPTOCOCCUS THERMOPHILUS
• Cellular location: Membrane; Multi-pass membrane protein (By similarity): Q5M4H8
• Total number of polymer chains: 2
• Total formula weight: 107554.66

Authors

Solcan, N.,Kwok, J.,Fowler, P.W.,Cameron, A.D.,Drew, D.,Iwata, S.,Newstead, S. (deposition date: 2012-04-05, release date: 2012-06-13, Last modification date: 2024-05-08)

Primary citation

Solcan, N.,Kwok, J.,Fowler, P.W.,Cameron, A.D.,Drew, D.,Iwata, S.,Newstead, S.
Alternating Access Mechanism in the Pot Family of Oligopeptide Transporters.
Embo J., 31:3411-, 2012

PubMed Abstract: Short chain peptides are actively transported across membranes as an efficient route for dietary protein absorption and for maintaining cellular homeostasis. In mammals, peptide transport occurs via PepT1 and PepT2, which belong to the proton-dependent oligopeptide transporter, or POT family. The recent crystal structure of a bacterial POT transporter confirmed that they belong to the major facilitator superfamily of secondary active transporters. Despite the functional characterization of POT family members in bacteria, fungi and mammals, a detailed model for peptide recognition and transport remains unavailable. In this study, we report the 3.3-Å resolution crystal structure and functional characterization of a POT family transporter from the bacterium Streptococcus thermophilus. Crystallized in an inward open conformation the structure identifies a hinge-like movement within the C-terminal half of the transporter that facilitates opening of an intracellular gate controlling access to a central peptide-binding site. Our associated functional data support a model for peptide transport that highlights the importance of salt bridge interactions in orchestrating alternating access within the POT family.

PubMed: 22659829
DOI: 10.1038/EMBOJ.2012.157

Experimental method

X-RAY DIFFRACTION (3.3 Å)