Structure of the zinc transporter YiiP.
YiiP is a membrane transporter that catalyzes Zn2+/H+ exchange across the inner membrane of Escherichia coli. Mammalian homologs of YiiP play critical roles in zinc homeostasis and cell signaling. Here, we report the x-ray structure of YiiP in complex with zinc at 3.8 angstrom resolution. YiiP is a homodimer held together in a parallel orientation through four Zn2+ ions at the interface of the cytoplasmic domains, whereas the two transmembrane domains swing out to yield a Y-shaped structure. In each protomer, the cytoplasmic domain adopts a metallochaperone-like protein fold; the transmembrane domain features a bundle of six transmembrane helices and a tetrahedral Zn2+ binding site located in a cavity that is open to both the membrane outer leaflet and the periplasm.
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Department of Biology, Brookhaven National Laboratory, Upton, NY 11973, USA.
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D000595:Amino Acid Sequence; D001665:Binding Sites; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000737:chemistry / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D016415:Sequence Alignment; D015032:Zinc / Q000737:chemistry* / Q000378:metabolism
D029968:Escherichia coli Proteins; D026901:Membrane Transport Proteins; C486459:YiiP protein, E coli; D015032:Zinc