zinc efflux transmembrane transporter activity / zinc ion import across plasma membrane / solute:proton symporter activity / zinc ion transmembrane transporter activity / cobalt ion transmembrane transporter activity / zinc ion transmembrane transport / magnesium ion transmembrane transporter activity / cobalt ion binding / magnesium ion binding / plasma membrane 類似検索 - 分子機能
Zinc transport protein ZntB / Mg2+ transporter protein, CorA-like/Zinc transport protein ZntB / CorA, cytoplasmic domain / CorA, transmembrane region / CorA-like Mg2+ transporter protein 類似検索 - ドメイン・相同性
ジャーナル: Nat Commun / 年: 2017 タイトル: The structural basis of proton driven zinc transport by ZntB. 著者: Cornelius Gati / Artem Stetsenko / Dirk J Slotboom / Sjors H W Scheres / Albert Guskov / 要旨: Zinc is an essential microelement to sustain all forms of life. However, excess of zinc is toxic, therefore dedicated import, export and storage proteins for tight regulation of the zinc ...Zinc is an essential microelement to sustain all forms of life. However, excess of zinc is toxic, therefore dedicated import, export and storage proteins for tight regulation of the zinc concentration have evolved. In Enterobacteriaceae, several membrane transporters are involved in zinc homeostasis and linked to virulence. ZntB has been proposed to play a role in the export of zinc, but the transport mechanism of ZntB is poorly understood and based only on experimental characterization of its distant homologue CorA magnesium channel. Here, we report the cryo-electron microscopy structure of full-length ZntB from Escherichia coli together with the results of isothermal titration calorimetry, and radio-ligand uptake and fluorescent transport assays on ZntB reconstituted into liposomes. Our results show that ZntB mediates Zn uptake, stimulated by a pH gradient across the membrane, using a transport mechanism that does not resemble the one proposed for homologous CorA channels.