7ZC2
Dipeptide and tripeptide Permease C (DtpC)
Summary for 7ZC2
| Entry DOI | 10.2210/pdb7zc2/pdb |
| EMDB information | 14618 |
| Descriptor | Amino acid/peptide transporter (1 entity in total) |
| Functional Keywords | membrane protein, peptide transporter, proton coupled oligopeptide transporter, pot, mfs, dtpc., transport protein |
| Biological source | Escherichia coli |
| Total number of polymer chains | 1 |
| Total formula weight | 53090.27 |
| Authors | Killer, M.,Finocchio, G.,Pardon, E.,Steyaert, J.,Loew, C. (deposition date: 2022-03-25, release date: 2022-07-06, Last modification date: 2024-07-24) |
| Primary citation | Killer, M.,Finocchio, G.,Mertens, H.D.T.,Svergun, D.I.,Pardon, E.,Steyaert, J.,Low, C. Cryo-EM Structure of an Atypical Proton-Coupled Peptide Transporter: Di- and Tripeptide Permease C. Front Mol Biosci, 9:917725-917725, 2022 Cited by PubMed Abstract: 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 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 Å. 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. PubMed: 35898305DOI: 10.3389/fmolb.2022.917725 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (2.72 Å) |
Structure validation
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