Liu Xianxian, Wood Piper L, Parales Juanito V, Parales Rebecca E
Department of Microbiology, 226 Briggs Hall, 1 Shields Ave., University of California, Davis, CA 95616, USA.
J Bacteriol. 2009 May;191(9):2909-16. doi: 10.1128/JB.01708-08. Epub 2009 Feb 27.
We developed a high-throughput quantitative capillary assay and demonstrated that Pseudomonas putida strains F1 and PRS2000 were attracted to cytosine, but not thymine or uracil. In contrast, Pseudomonas aeruginosa PAO1 was not chemotactic to any pyrimidines. Chemotaxis assays with a mutant strain of F1 in which the putative methyl-accepting chemotaxis protein-encoding gene Pput_0623 was deleted revealed that this gene (designated mcpC) encodes a chemoreceptor for positive chemotaxis to cytosine. P. putida F1 also responded weakly to cytidine, uridine, and thymidine, but these responses were not mediated by mcpC. Complementation of the F1 DeltamcpC mutant XLF004 with the wild-type gene restored chemotaxis to cytosine. In addition, introduction of this gene into P. aeruginosa PAO1 conferred the ability to respond to cytosine. To our knowledge, this is the first report of a chemoreceptor for cytosine.
我们开发了一种高通量定量毛细管测定法，并证明恶臭假单胞菌菌株F1和PRS2000被胞嘧啶吸引，但不被胸腺嘧啶或尿嘧啶吸引。相比之下，铜绿假单胞菌PAO1对任何嘧啶都没有趋化性。对F1的一个突变菌株进行趋化性测定，其中假定的甲基接受趋化蛋白编码基因Pput_0623被删除，结果表明该基因（命名为mcpC）编码一种对胞嘧啶产生正向趋化性的化学感受器。恶臭假单胞菌F1对胞苷、尿苷和胸苷也有微弱反应，但这些反应不是由mcpC介导的。用野生型基因对F1 DeltamcpC突变体XLF004进行互补恢复了对胞嘧啶的趋化性。此外，将该基因导入铜绿假单胞菌PAO1赋予了其对胞嘧啶作出反应的能力。据我们所知，这是关于胞嘧啶化学感受器的首次报道。
