Variation in RNA polymerase sigma subunit composition within different stocks of Escherichia coli W3110
Variation in RNA polymerase sigma subunit composition within different stocks of Escherichia coli W3110
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DOI：
10.1128/jb.179.3.959-963.1997
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发表时间：
1997-02-01
影响因子：
3.2
通讯作者：
Ishihama, A
中科院分区：
文献类型：
--
作者：
Jishage, M;Ishihama, A
对日本来源的大肠杆菌K-12 W3110菌株的RNA聚合酶西格玛亚基组成进行了分析。Sigma(28)(RpoF基因产物sigma(F))和Sigma(38)(RpoS基因产物Sigma(S))是两个Sigma亚基的异质性。我们鉴定了五种不同类型的W3110：A型谱系具有两个完整形式的A亚基；B型谱系携带截短的sigma(38)亚基和完整的sigma(28)亚基；C型谱系携带完整的sigma(28)亚基，但缺少sigma(38)亚基；D型谱系仅具有sigma(38)亚基而没有sigma(28)亚基；以及E类股票缺少这两个sigma亚基。然而，所有被检测的谱系都含有完整形式的sigma(70)(rpoD基因产物sigma(D))和sigma(54)(rpoN基因产物sigma(N))。由于缺乏Sigma(28)亚单位，D型和E型血统的细胞是不活动的。在B型股票中，Sigma(38)亚基的截短形式在其N端附近带有两个突变，并且由于琥珀突变而缺乏C-末端近端区域4。C型和E型W3110细胞未能表达sigma(38)，而D型和E型细胞未能表达sigma(28)，这是由于转录缺陷造成的，尽管各自的a亚单位基因保持完整。这些发现强调了关注源自同一菌株的实验室种群之间可能存在的遗传背景差异的重要性。
The composition of RNA polymerase sigma subunits was analyzed for stock strains of Escherichia coli K-12 W3110 in Japan. Heterogeneity was discovered with respect to two sigma subunits, sigma(28) (sigma(F), the rpoF gene product) and sigma(38) (sigma(S), the rpoS gene product). Five different types of W3110 were identified: A-type lineages have both a subunits in intact forms; B-type lineages carry a truncated sigma(38) subunit and an intact sigma(28) subunit; C-type lineages carry an intact sigma(28) subunit but lack a sigma(38) subunit; D-type lineages have only a sigma(38) subunit without a sigma(28) subunit; and E-type stocks lack both sigma subunits. All the lineages examined, however, contain the intact forms of sigma(70) (sigma(D), the rpoD gene product) and sigma(54) (sigma(N), the rpoN gene product). As expected from the lack of a sigma(28) subunit, cells of D- and E-type lineages are nonmotile. The truncated form of the sigma(38) subunit in B-type stocks carries two mutations near its N terminus and lacks C-terminal proximal region 4 due to an amber mutation. The failure of C- and E-type W3110 cells to express sigma(38) and that of D- and E-type cells to express sigma(28) were found to be due to defects in transcription even though the respective a subunit genes remain intact. These findings emphasize the importance of paying attention to possible variations in the genetic background between laboratory stocks originating from the same strain.