GabR, a member of a novel protein family, regulates the utilization of γ-aminobutyrate in Bacillus subtilis
GabR, a member of a novel protein family, regulates the utilization of γ-aminobutyrate in Bacillus subtilis
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DOI：
10.1046/j.1365-2958.2002.03036.x
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发表时间：
2002-07-01
影响因子：
3.6
通讯作者：
Sonenshein, AL
中科院分区：
文献类型：
--
作者：
Belitsky, BR;Sonenshein, AL
枯草芽孢杆菌ycnG（gabT）和ycnH（gabD）基因分别编码γ-氨基丁酸（GABA）氨基转移酶和琥珀酸半醛脱氢酶，并形成GABA诱导的操纵子。gabT、gabD或差异转录的ycnF（gabR）基因的突变阻断了GABA作为唯一氮源的利用。GabR被证明是gabTD操纵子的转录激活因子和负性自动调节因子。GabR作用的靶定位于包括gabR和gabT启动子的87 bp区域。GabR是一个新的但广泛的嵌合细菌蛋白家族的成员，具有明显的DNA结合和氨基转移酶结构域。假定的氨基转移酶结构域的保守残基的突变废除了GabR作为转录激活因子的功能，但不影响其作为负性自身调节因子的活性。
The Bacillus subtilis ycnG (gabT) and ycnH (gabD) genes were shown to encode gamma-aminobutyrate (GABA) aminotransferase and succinic semi-aldehyde dehydrogenase, respectively, and to form a GABA-inducible operon. Null mutations in gabT, gabD or the divergently transcribed ycnF (gabR) gene blocked the utilization of GABA as sole nitrogen source. GabR proved to be a transcriptional activator of the gabTD operon and a negative autoregulator. The target of GabR action was localized to an 87 bp region that includes both gabR and gabT promoters. GabR is a member of a novel but widespread family of chimeric bacterial proteins that have apparent DNA-binding and aminotransferase domains. Mutations in conserved residues of the putative aminotransferase domain abolished GabR function as a transcriptional activator, but did not affect its activity as a negative autoregulator.