7Z6M

Crystal structure of Zn2+-transporter BbZIP in a cadmium bound state

Summary for 7Z6M

• Entry DOI: 10.2210/pdb7z6m/pdb
• Related: 5TSA
• Descriptor: Putative membrane protein, CADMIUM ION (2 entities in total)
• Functional Keywords: zinc transporters, zrt/irt-like proteins (zips), solute carrier 39 (slc39) family, bbzip, transport mechanism, elevator mechanism, membrane protein, metal transport
• Biological source: Bordetella bronchiseptica
• Total number of polymer chains: 1
• Total formula weight: 33630.29

Authors

Wiuf, A.,Steffen, J.H.,Becares, E.R.,Groenberg, C.,Mahato, D.R.,Rasmussen, S.G.F.,Andersson, M.,Croll, T.,Gotfryd, K.,Gourdon, P. (deposition date: 2022-03-13, release date: 2022-08-10, Last modification date: 2024-01-31)

Primary citation

Wiuf, A.,Steffen, J.H.,Becares, E.R.,Gronberg, C.,Mahato, D.R.,Rasmussen, S.G.F.,Andersson, M.,Croll, T.,Gotfryd, K.,Gourdon, P.
The two-domain elevator-type mechanism of zinc-transporting ZIP proteins.
Sci Adv, 8:eabn4331-eabn4331, 2022

PubMed Abstract: Zinc is essential for all organisms and yet detrimental at elevated levels. Hence, homeostasis of this metal is tightly regulated. The Zrt/Irt-like proteins (ZIPs) represent the only zinc importers in metazoans. Mutations in human ZIPs cause serious disorders, but the mechanism by which ZIPs transfer zinc remains elusive. Hitherto, structural information is only available for a model member, BbZIP, and as a single, ion-bound conformation, precluding mechanistic insights. Here, we elucidate an inward-open metal-free BbZIP structure, differing substantially in the relative positions of the two separate domains of ZIPs. With accompanying coevolutional analyses, mutagenesis, and uptake assays, the data point to an elevator-type transport mechanism, likely shared within the ZIP family, unifying earlier functional data. Moreover, the structure reveals a previously unknown ninth transmembrane segment that is important for activity in vivo. Our findings outline the mechanistic principles governing ZIP-protein transport and enhance the molecular understanding of ZIP-related disorders.

PubMed: 35857505
DOI: 10.1126/sciadv.abn4331

Experimental method

X-RAY DIFFRACTION (2.51 Å)