7zc2

Dipeptide and tripeptide Permease C (DtpC)

spinqualitylabelsall models 7zc2, resolution 2.72Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 7zc2 is a 1 chain structure with sequence from Escherichia coli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Electron Microscopy, Resolution 2.72Å Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function DTPC_ECOLI Proton-dependent permease that transports di- and tripeptides. Shows significantly higher specificity towards dipeptides than tripeptides. Has a preference for dipeptides with a C-terminal Lys residue. Can bind Ala-Lys, Lys-Ala, Ala-Ala. Can also transport alanine and trialanine. Publication Abstract from PubMed Proton-coupled Oligopeptide Transporters (POTs) of the Major Facilitator Superfamily (MFS) mediate the uptake of short di- and tripeptides in all phyla of life. POTs are thought to constitute the most promiscuous class of MFS transporters, with the potential to transport more than 8400 unique substrates. Over the past two decades, transport assays and biophysical studies have shown that various orthologues and paralogues display differences in substrate selectivity. The E. coli genome codes for four different POTs, known as Di- and tripeptide permeases A-D (DtpA-D). DtpC was shown previously to favor positively charged peptides as substrates. In this study, we describe, how we determined the structure of the 53 kDa DtpC by cryogenic electron microscopy (cryo-EM), and provide structural insights into the ligand specificity of this atypical POT. We collected and analyzed data on the transporter fused to split superfolder GFP (split sfGFP), in complex with a 52 kDa Pro-macrobody and with a 13 kDa nanobody. The latter sample was more stable, rigid and a significant fraction dimeric, allowing us to reconstruct a 3D volume of DtpC at a resolution of 2.7 A. This work provides a molecular explanation for the selectivity of DtpC, and highlights the value of small and rigid fiducial markers such as nanobodies for structure determination of low molecular weight integral membrane proteins lacking soluble domains. Cryo-EM Structure of an Atypical Proton-Coupled Peptide Transporter: Di- and Tripeptide Permease C.,Killer M, Finocchio G, Mertens HDT, Svergun DI, Pardon E, Steyaert J, Low C Front Mol Biosci. 2022 Jul 11;9:917725. doi: 10.3389/fmolb.2022.917725. , eCollection 2022. PMID:35898305 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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