A novel toxin–antitoxin operon talA/B from the Gram-positive bacterium Leifsonia xyli subsp. cynodontis

Cheng, Lin; Lin, Hui; Fan, Xuelian; Qiu, Shi; Sun, Tao; Li, Tai-Yuan; Zhang, Yi

doi:10.1016/j.febslet.2008.08.012

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Volume 582, Issue 21 , Pages 3211-3216, 22 September 2008

A novel toxin–antitoxin operon talA/B from the Gram-positive bacterium Leifsonia xyli subsp. cynodontis

Edited by Gianni Cesareni

Lin Cheng
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Hubei 430072, China
Hui Lin
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Hubei 430072, China
Xuelian Fan
- College of Plant Sciences, Huazhong Agricultural University, China
Shi Qiu
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Hubei 430072, China
Tao Sun
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Hubei 430072, China
Tai-Yuan Li
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Hubei 430072, China
- Corresponding authors. Fax: +86 27 68754945.
Yi Zhang
- State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Hubei 430072, China
- Corresponding authors. Fax: +86 27 68754945.

Received 21 May 2008; received in revised form 31 July 2008; accepted 3 August 2008. published online 21 August 2008.

Abstract

Here we report a toxin–antitoxin (TA) operon talAB identified from the Gram-positive bacterium Leifsonia xyli subsp. cynodontis. It is shown that talB encodes a broad-host cytotoxin functioning in different Gram-positive bacteria, while talA encodes its antidote. TalA and TalB form different hetero-oligomers in vitro; these hetero-oligomers, but not the antitoxin TalA, strongly bind to the talAB promoter region containing two inverted repeats. This represents a new mechanism of binding the promoter of a TA operon by the toxin and antitoxin complexes.

Abbreviations: TA, toxin–antitoxin, EGS, ethylene glycol-bis

Keywords: talA/B, Toxin–antitoxin, Promoter binding, Leifsonia xyli subsp. Cynodontis