Planar substrate-binding site dictates the specificity of ECF-type nickel/cobalt transporters

CORC > 上海应用物理研究所 > 中国科学院上海应用物理研究所 > 中科院上海应用物理研究所2011-2017年

	Planar substrate-binding site dictates the specificity of ECF-type nickel/cobalt transporters
	Yu, Y ; Zhou, MZ ; Kirsch, F ; Xu, CQ ; Zhang, L ; Wang, Y ; Jiang, Z ; Wang, N ; Li, J ; Eitinger, T ; Yang, MJ
刊名	CELL RESEARCH
	2014
卷号	24 期号:3 页码:267—277
关键词	COUPLING FACTOR TRANSPORTER CRYSTAL-STRUCTURE ATCUN MOTIF ABC TRANSPORTERS MG2+ TRANSPORTER METAL-BINDING NEUROMEDIN-C NICKEL VITAMIN-B-12 PROTEINS
ISSN号	1001-0602
通讯作者	junli@tsinghua.edu.cn ; thomas.eitinger@cms.hu-berlin.de ; maojunyang@tsinghua.edu.cn
英文摘要	The energy-coupling factor (ECF) transporters are multi-subunit protein complexes that mediate uptake of transition-metal ions and vitamins in about 50% of the prokaryotes, including bacteria and archaea. Biological and structural studies have been focused on ECF transporters for vitamins, but the molecular mechanism by which ECF systems transport metal ions from the environment remains unknown. Here we report the first crystal structure of a NikM, TtNikM2, the substrate-binding component (S component) of an ECF-type nickel transporter from Thermoanaerobacter tengcongensis. In contrast to the structures of the vitamin-specific S proteins with six transmembrane segments (TSs), TtNikM2 possesses an additional TS at its N-terminal region, resulting in an extracellular N-terminus. The highly conserved N-terminal loop inserts into the center of TtNikM2 and occludes a region corresponding to the substrate-binding sites of the vitamin-specific S components. Nickel binds to NikM via its coordination to four nitrogen atoms, which are derived from Met1, His2 and His67 residues. These nitrogen atoms form an approximately square-planar geometry, similar to that of the metal ion-binding sites in the amino-terminal Cu2+-and Ni2+-binding (ATCUN) motif. Replacements of residues in NikM contributing to nickel coordination compromised the Ni-transport activity. Furthermore, systematic quantum chemical investigation indicated that this geometry enables NikM to also selectively recognize Co2+. Indeed, the structure of TtNikM2 containing a bound Co2+ ion has almost no conformational change compared to the structure that contains a nickel ion. Together, our data reveal an evolutionarily conserved mechanism underlying the metal selectivity of EcfS proteins, and provide insights into the ion-translocation process mediated by ECF transporters.
收录类别	SCI
语种	英语
WOS记录号	WOS:000332246500005
公开日期	2015-03-13
内容类型	期刊论文
源URL	[http://ir.sinap.ac.cn/handle/331007/14318]
专题	上海应用物理研究所_中科院上海应用物理研究所2011-2017年
推荐引用方式 GB/T 7714	Yu, Y,Zhou, MZ,Kirsch, F,et al. Planar substrate-binding site dictates the specificity of ECF-type nickel/cobalt transporters[J]. CELL RESEARCH,2014,24(3):267—277.
APA	Yu, Y.,Zhou, MZ.,Kirsch, F.,Xu, CQ.,Zhang, L.,...&Yang, MJ.(2014).Planar substrate-binding site dictates the specificity of ECF-type nickel/cobalt transporters.CELL RESEARCH,24(3),267—277.
MLA	Yu, Y,et al."Planar substrate-binding site dictates the specificity of ECF-type nickel/cobalt transporters".CELL RESEARCH 24.3(2014):267—277.