title: Crystal structure of the vitamin B3 transporter PnuC, a full-length SWEET homolog.
abstract: PnuC transporters catalyze cellular uptake of the NAD+ precursor nicotinamide riboside (NR) and belong to a large superfamily that includes the SWEET sugar transporters. We present a crystal structure of Neisseria mucosa PnuC, which adopts a highly symmetrical fold with 3+1+3 membrane topology not previously observed in any protein. The high symmetry of PnuC with a single NR bound in the center suggests a simple alternating-access translocation mechanism.
authors.affiliation: University of Groningen, Groningen Biomolecular Sciences and Biotechnology Institute, Groningen, the Netherlands.
authors.forename: Michael
authors.initials: M
authors.lastname: Jaehme
authors.affiliation: University of Groningen, Groningen Biomolecular Sciences and Biotechnology Institute, Groningen, the Netherlands.
authors.forename: Albert
authors.identifier: 0000000323402216
authors.initials: A
authors.lastname: Guskov
authors.affiliation: University of Groningen, Groningen Biomolecular Sciences and Biotechnology Institute, Groningen, the Netherlands.
authors.forename: Dirk Jan
authors.initials: DJ
authors.lastname: Slotboom
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics; D001665:Binding Sites; D001692:Biological Transport; D017124:Conserved Sequence; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D008958:Models, Molecular; D008969:Molecular Sequence Data; D042807:Neisseria mucosa / Q000737:chemistry* / Q000378:metabolism; D009536:Niacinamide / Q000031:analogs & derivatives* / Q000737:chemistry*; D011485:Protein Binding; D011487:Protein Conformation; D017510:Protein Folding; D011726:Pyridinium Compounds; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity
chemical_list: D001426:Bacterial Proteins; D011726:Pyridinium Compounds; D011994:Recombinant Proteins; C018613:nicotinamide-beta-riboside; D009536:Niacinamide