The Escherichia coli K-12 F plasmid gene traX is required for acetylation of F pilin.
The Escherichia coli K-12 F plasmid gene traX is required for acetylation of F pilin.
复制标题
F 菌毛蛋白乙酰化需要大肠杆菌 K-12 F 质粒基因 traX。
DOI：
10.1128/jb.175.5.1375-1383.1993
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发表时间：
1993
影响因子：
3.2
通讯作者：
Ippen-Ihler,K
中科院分区：
文献类型：
--
作者：
Moore,D;Hamilton,CM;Maneewannakul,K;Mintz,Y;Frost,LS;Ippen-Ihler,K
鉴定了大肠杆菌F-菌毛蛋白亚基氨基末端乙酰化所需的F质粒基因。使用Western印迹（免疫印迹），我们测定了反应的单克隆抗体与F-菌毛蛋白多肽的内膜制剂从各种F突变株。已知JEL 92识别内部菌毛蛋白表位，JEL 93识别乙酰化氨基末端序列（L.S.弗罗斯特，J.S.李，D. G. Scraba和W. Paranchych，J. Bacteriol. 168：192-198，1986）。正如预期的那样，两种抗体都不与来自F-细胞的内膜或不合成菌毛蛋白的Flac衍生物反应。影响Ftra基因traA、-B、-C、-D、-E、-F、-G、-H、-I、-J、-K、-L、-M、-N、-P、-R、-U、-V和-W或trB基因trbA、-B、-C、-D、-E、-G、-H和-I的个体活性的突变不阻止JEL 92或JEL 93识别膜菌毛蛋白。然而，缺乏最远端转移区基因的Hfr缺失突变体不表达与JEL 93反应的菌毛蛋白。然而，保留traA和traQ的所有菌株都表达JEL 92反应性菌毛蛋白多肽。对表达克隆的tra片段的菌株的分析表明，traA和traQ足以合成JEL 92反应性菌毛蛋白，但JEL 93反应性菌毛蛋白的合成另外依赖于traX。我们得出结论，traX产物是F菌毛蛋白乙酰化所必需的。有趣的是，我们的数据还显示，TraA+ TraQ+细胞合成两种形式的菌毛蛋白，其在约7和8 kDa处迁移。在TraX+细胞中，两者都被乙酰化并与JEL 93反应。制备的野生型F菌毛丝含有两种类型的亚基。
The Escherichia coli F plasmid gene required for amino-terminal acetylation of F-pilin subunits was identified. Using Western blots (immunoblots), we assayed the reaction of monoclonal antibodies with F-pilin polypeptides in inner membrane preparations from various F mutant strains. It was known that JEL92 recognizes an internal pilin epitope and JEL93 recognizes the acetylated amino-terminal sequence (L.S. Frost, J.S. Lee, D.G. Scraba, and W. Paranchych, J. Bacteriol. 168:192-198, 1986). As expected, neither antibody reacted with inner membranes from F- cells or Flac derivatives that do not synthesize pilin. Mutations that affected the individual activities of F tra genes traA, -B, -C, -D, -E, -F, -G, -H, -I, -J, -K, -L, -M, -N, -P, -R, -U, -V and -W or trb genes trbA, -B, -C, -D, -E, -G, -H, and -I did not prevent JEL92 or JEL93 recognition of membrane pilin. However, Hfr deletion mutants that lacked the most-distal transfer region genes did not express pilin that reacted with JEL93. Nevertheless, all strains that retained traA and traQ did express JEL92-reactive pilin polypeptides. Analysis of strains expressing cloned tra segments showed that traA and traQ suffice for synthesis of JEL92-reactive pilin, but synthesis of JEL93-reactive pilin is additionally dependent on traX. We concluded that the traX product is required for acetylation of F pilin. Interestingly, our data also showed that TraA+ TraQ+ cells synthesize two forms of pilin which migrate at approximately 7 and 8 kDa. In TraX+ cells, both become acetylated and react with JEL93. Preparations of wild-type F-pilus filaments contain both types of subunits.