5OXL

PepTSt in complex with dipeptide Ala-Leu

Summary for 5OXL

• Entry DOI: 10.2210/pdb5oxl/pdb
• Descriptor: Di-or tripeptide:H+ symporter, PHOSPHATE ION, 4-(2-HYDROXYETHYL)-1-PIPERAZINE ETHANESULFONIC ACID, ... (9 entities in total)
• Functional Keywords: alpha-helical membrane protein, mfs fold, membrane protein, peptide transporter, transport protein
• Biological source: Streptococcus thermophilus (strain ATCC BAA-250 / LMG 18311)
• Total number of polymer chains: 1
• Total formula weight: 57917.74

Authors

Martinez Molledo, M.,Quistgaard, E.M.,Loew, C. (deposition date: 2017-09-07, release date: 2018-02-21, Last modification date: 2024-01-17)

Primary citation

Martinez Molledo, M.,Quistgaard, E.M.,Flayhan, A.,Pieprzyk, J.,Low, C.
Multispecific Substrate Recognition in a Proton-Dependent Oligopeptide Transporter.
Structure, 26:467-476.e4, 2018

PubMed Abstract: Proton-dependent oligopeptide transporters (POTs) are important for uptake of dietary di- and tripeptides in many organisms, and in humans are also involved in drug absorption. These transporters accept a wide range of substrates, but the structural basis for how different peptide side chains are accommodated has so far remained obscure. Twenty-eight peptides were screened for binding to PepT from Streptococcus thermophilus, and structures were determined of PepT in complex with four physicochemically diverse dipeptides, which bind with millimolar affinity: Ala-Leu, Phe-Ala, Ala-Gln, and Asp-Glu. The structures show that PepT can adapt to different peptide side chains through movement of binding site residues and water molecules, and that a good fit can be further aided by adjustment of the position of the peptide itself. Finally, structures were also determined in complex with adventitiously bound HEPES, polyethylene glycol, and phosphate molecules, which further underline the adaptability of the binding site.

PubMed: 29429879
DOI: 10.1016/j.str.2018.01.005

Experimental method

X-RAY DIFFRACTION (2.66 Å)