THE BACILLUS-SUBTILIS FLAGELLIN GENE (HAG) IS TRANSCRIBED BY THE SIGMA-28 FORM OF RNA-POLYMERASE
THE BACILLUS-SUBTILIS FLAGELLIN GENE (HAG) IS TRANSCRIBED BY THE SIGMA-28 FORM OF RNA-POLYMERASE
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DOI：
10.1128/jb.171.6.3095-3101.1989
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发表时间：
1989-06-01
影响因子：
3.2
通讯作者：
CHAMBERLIN, MJ
中科院分区：
文献类型：
--
作者：
MIREL, DB;CHAMBERLIN, MJ
编码鞭毛蛋白结构蛋白的枯草芽孢杆菌基因hag是通过DNA序列分析在带有σ28形式RNA聚合酶的体外启动子的DNA片段集合中鉴定的。对hag基因和枯草芽孢杆菌染色体的邻近区域进行限制性图谱，并确定核苷酸序列。 had基因在所有生长阶段从单个启动子转录，启动子识别区中的had序列是σ28全酶共有序列的特征。 hag 的转录因插入突变而被消除，插入突变阻止了 σ28 蛋白的合成。这些发现为先前的提议提供了强有力的支持，即RNA聚合酶的.sigma.28形式控制枯草芽孢杆菌中指定鞭毛、趋化性和运动功能的调节子的转录(J.D.Helmann和M.J.Chamberlin，Proc.Natl.Acd.Sci.USA 84：6422-6424，1987)。 hag mRNA 的稳态水平在指数生长过程中增加，并在枯草芽孢杆菌细胞进入稳定期时达到峰值。孢子形成后 4 小时内转录水平降至零。因此，σ28 RNA聚合酶功能受到暂时调节。
The Bacillus subtilis gene hag, which codes for the flagellin structural prot ein, was identified by DNA sequence analysis in a collection of DNA fragments bearing in vitro promoters for the .sigma.28 form of RNA polymerase. The hag gene and adjacent regions of the B. subtilis chromosome were restriction mapped, and the nucleotide sequence was determined. The had gene was transcribed at all stages of growth from a single promoter than had sequences in the promoter recognition region characteristic of the consensus sequence for the .sigma.28 holoenzyme. Transcription of hag was eliminated by insertion mutations that blocked synthesis of the .sigma.28 protein. These findings provide strong support for the previous proposal that the .sigma.28 form of RNA polymerase controls transcription of a regulon specifying flagellar, chemotaxis, and motility functions in B. subtilis (J. D. Helmann and M. J. Chamberlin, Proc. Natl. Acd. Sci. USA 84:6422-6424, 1987). The steady-state levels of hag mRNA increased during exponential growth and peaked as the B. subtilis cells entered the stationary phase. The transcript levels then decreased to zero within 4 h after the onset of sporulation. Hence, .sigma.28 RNA polymerase function is temporally regulated.