Structural basis for dynamic mechanism of nitrate/nitrite antiport by NarK

被引：49

作者：

Fukuda, Masahiro ^{[1
,2
]}

Takeda, Hironori ^{[1
,2
]}

Kato, Hideaki E. ^{[1
,2
]}

Doki, Shintaro ^{[1
,2
]}

Ito, Koichi ^{[3
]}

Maturana, Andres D. ^{[4
]}

Ishitani, Ryuichiro ^{[1
,2
]}

Nureki, Osamu ^{[1
,2
]}

机构：

[1] Univ Tokyo, Grad Sch Sci, Dept Biol Sci, Bunkyo Ku, Tokyo 1130033, Japan

[2] RIKEN, Global Res Cluster, Saitama 3510198, Japan

[3] Univ Tokyo, Grad Sch Frontier Sci, Dept Med Genome Sci, Kashiwa, Chiba 2778562, Japan

[4] Nagoya Univ, Grad Sch Bioagr Sci, Dept Bioengn Sci, Chikusa Ku, Nagoya, Aichi 4648601, Japan

来源：

NATURE COMMUNICATIONS | 2015年 / 6卷

基金：

日本学术振兴会; 日本科学技术振兴机构;

关键词：

ESCHERICHIA-COLI K-12; NITRATE TRANSPORTERS; CRYSTAL-STRUCTURE; RESPIRATION; PROTEIN; SYSTEM; REDUCTASE; PHENIX; NIRC;

D O I：

10.1038/ncomms8097

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

NarK belongs to the nitrate/nitrite porter (NNP) family in the major facilitator superfamily (MFS) and plays a central role in nitrate uptake across the membrane in diverse organisms, including archaea, bacteria, fungi and plants. Although previous studies provided insight into the overall structure and the substrate recognition of NarK, its molecular mechanism, including the driving force for nitrate transport, remained elusive. Here we demonstrate that NarK is a nitrate/nitrite antiporter, using an in vitro reconstituted system. Furthermore, we present the high-resolution crystal structures of NarK from Escherichia coli in the nitrate-bound occluded, nitrate-bound inward-open and apo inward-open states. The integrated structural, functional and computational analyses reveal the nitrate/nitrite antiport mechanism of NarK, in which substrate recognition is coupled to the transport cycle by the concomitant movement of the transmembrane helices and the key tyrosine and arginine residues in the substrate-binding site.

引用

页数：12

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