参与嗜碱假单胞菌重金属稳态转录调控的双组分调节系统。

Two-component regulatory system involved in transcriptional control of heavy-metal homoeostasis in Alcaligenes eutrophus.

作者信息

van der Lelie D, Schwuchow T, Schwidetzky U, Wuertz S, Baeyens W, Mergeay M, Nies D H

机构信息

Environmental Technology, VITO, Mol, Belgium.

出版信息

Mol Microbiol. 1997 Feb;23(3):493-503. doi: 10.1046/j.1365-2958.1997.d01-1866.x.

DOI:10.1046/j.1365-2958.1997.d01-1866.x

PMID:9044283

Abstract

The czc determinant, which mediates resistance to Co2+, Zn2+ and Cd2+ in Alcaligenes eutrophus CH34 by cation efflux, is regulated by a two-component regulatory system composed of the sensor histidine kinase CzcS and the response activator CzcR (in addition to other components previously described). Regulatory genes are arranged in an upstream regulatory region (URR) and a downstream regulatory region (DRR). Transcription of czcCBA and of the URR was regulated by heavy-metal cations. DNA sequencing of the region downstream of czcD revealed the presence of the czcR and czcS genes which together with czcD form the DRR. Regulation of the DRR was studied with a czcD::lacZ translational fusion and a czcS::lux transcriptional fusion. Expression of both genes is also regulated by heavy metals. The genes of the URR yielded three mRNAs of approx. 1200, 500 and 200 nucleotides, respectively. The genes czcCBA for the cation/proton antiporter CzcCBA were transcribed by one operon as a transcript of 6200 nucleotides.

摘要

czc决定簇通过阳离子外流介导嗜碱假单胞菌CH34对Co2+、Zn2+和Cd2+的抗性，它受由传感器组氨酸激酶CzcS和应答激活剂CzcR组成的双组分调节系统调控（除先前描述的其他组分外）。调控基因排列在上游调控区（URR）和下游调控区（DRR）。czcCBA和URR的转录受重金属阳离子调控。czcD下游区域的DNA测序揭示了czcR和czcS基因的存在，它们与czcD一起构成DRR。利用czcD::lacZ翻译融合和czcS::lux转录融合研究了DRR的调控。这两个基因的表达也受重金属调控。URR的基因分别产生了约1200、500和200个核苷酸的三种mRNA。阳离子/质子反向转运蛋白CzcCBA的基因czcCBA由一个操纵子转录为6200个核苷酸的转录本。