著者
Tohru Minamino Miki Kinoshita Yusuke V. Morimoto Keiichi Namba
出版者
The Biophysical Society of Japan
雑誌
Biophysics and Physicobiology (ISSN:21894779)
巻号頁・発行日
pp.e190046, (Released:2022-11-19)
被引用文献数
3

Bacteria employ the flagellar type III secretion system (fT3SS) to construct flagellum, which acts as a supramolecular motility machine. The fT3SS of Salmonella enterica serovar Typhimurium is composed of a transmembrane export gate complex and a cytoplasmic ATPase ring complex. The transmembrane export gate complex is fueled by proton motive force across the cytoplasmic membrane and is divided into four distinct functional parts: a dual-fuel export engine; a polypeptide channel; a membrane voltage sensor; and a docking platform. ATP hydrolysis by the cytoplasmic ATPase complex converts the export gate complex into a highly efficient proton (H+)/ protein antiporter that couples inward-directed H+ flow with outward-directed protein export. When the ATPase ring complex does not work well in a given environment, the export gate complex will remain inactive. However, when the electric potential difference, which is defined as membrane voltage, rises above a certain threshold value, the export gate complex becomes an active H+/protein antiporter to a considerable degree, suggesting that the export gate complex has a voltage-gated activation mechanism. Furthermore, the export gate complex also has a sodium ion (Na+) channel to couple Na+ influx with flagellar protein export. In this article, we review our current understanding of the activation mechanism of the dual-fuel protein export engine of the fT3SS. This review article is an extended version of a Japanese article, Membrane voltage-dependent activation of the transmembrane export gate complex in the bacterial flagellar type III secretion system, published in SEIBUTSU BUTSURI Vol. 62, p165–169 (2022).
著者
Tohru Minamino Miki Kinoshita Yusuke V. Morimoto Keiichi Namba
出版者
The Biophysical Society of Japan
雑誌
Biophysics and Physicobiology (ISSN:21894779)
巻号頁・発行日
vol.19, pp.e190046, 2022 (Released:2022-12-07)
参考文献数
83
被引用文献数
3

Bacteria employ the flagellar type III secretion system (fT3SS) to construct flagellum, which acts as a supramolecular motility machine. The fT3SS of Salmonella enterica serovar Typhimurium is composed of a transmembrane export gate complex and a cytoplasmic ATPase ring complex. The transmembrane export gate complex is fueled by proton motive force across the cytoplasmic membrane and is divided into four distinct functional parts: a dual-fuel export engine; a polypeptide channel; a membrane voltage sensor; and a docking platform. ATP hydrolysis by the cytoplasmic ATPase complex converts the export gate complex into a highly efficient proton (H+)/protein antiporter that couples inward-directed H+ flow with outward-directed protein export. When the ATPase ring complex does not work well in a given environment, the export gate complex will remain inactive. However, when the electric potential difference, which is defined as membrane voltage, rises above a certain threshold value, the export gate complex becomes an active H+/protein antiporter to a considerable degree, suggesting that the export gate complex has a voltage-gated activation mechanism. Furthermore, the export gate complex also has a sodium ion (Na+) channel to couple Na+ influx with flagellar protein export. In this article, we review our current understanding of the activation mechanism of the dual-fuel protein export engine of the fT3SS. This review article is an extended version of a Japanese article, Membrane voltage-dependent activation of the transmembrane export gate complex in the bacterial flagellar type III secretion system, published in SEIBUTSU BUTSURI Vol. 62, p165–169 (2022).