IDENTIFICATION OF COMS, A GENE OF THE SRFA OPERON THAT REGULATES THE ESTABLISHMENT OF GENETIC COMPETENCE IN BACILLUS-SUBTILIS
IDENTIFICATION OF COMS, A GENE OF THE SRFA OPERON THAT REGULATES THE ESTABLISHMENT OF GENETIC COMPETENCE IN BACILLUS-SUBTILIS
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DOI：
10.1073/pnas.91.20.9397
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发表时间：
1994-09-27
影响因子：
11.1
通讯作者：
ZUBER, P
中科院分区：
文献类型：
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作者：
DSOUZA, C;NAKANO, MM;ZUBER, P
枯草芽孢杆菌的遗传能力（内化外源 DNA 的能力）取决于激活一系列能力特异性基因表达的调控途径。 srfA操纵子编码表面活性素合成酶的亚基，催化肽类抗生素表面活性素的非核糖体合成，也在能力调节途径中发挥作用。仅编码表面活性素合成酶七个氨基酸激活结构域之一的缬氨酸激活结构域 (srfAB1) 的 DNA 是能力所必需的。删除分析显示，srfAB1 的 569 bp 片段与 srfA 启动子融合，在能力方面补充了 srfA 删除突变 (Delta srfA)。该片段包含由 46 个氨基酸 (orf46) 组成的开放阅读框，与 srfAB1 不符。 orf46 上游 srfAB 中的移码突变对能力没有影响，但 orf46 中的移码和无义突变导致无法补充 Delta srfA 突变。这些结果表明 orf46 编码 srfA 相关的能力调节因子。假定的 orf46 产物 (ComS) 的计算机辅助分析显示与真核转录调节因子 POU 结构域类的同源结构域相似。
Genetic competence (the ability to internalize exogenous DNA) in Bacillus subtilis is dependent on a regulatory pathway that activates the expression of a battery of competence-specific genes. The srfA operon, encoding the subunits of surfactin synthetase, which catalyzes the nonribosomal synthesis of the peptide antibiotic surfactin, also functions in the competence regulatory pathway. The DNA encoding only one of the seven amino acid-activating domains of surfactin synthetase, the valine-activating domain (srfAB1), is necessary for competence. Deletion analysis revealed that a 569-bp fragment of srfAB1, fused to the srfA promoter, complements a srfA deletion mutation (Delta srfA) with respect to competence. This fragment contains an open reading frame consisting of 46 amino acids (orf46), which is out of frame with srfAB1. A frameshift mutation in srfAB upstream of orf46 has no effect on competence but a frameshift and nonsense mutation in orf46 resulted in failure to complement the Delta srfA mutation. These results indicate that orf46 encodes the srfA-associated competence regulatory factor. Computer-aided analysis of the putative orf46 product (ComS) shows similarity to the homeodomain of the POU domain class of eukaryotic transcriptional regulators.