Braud Sandrine, Lavire Celine, Bellier Audrey, Mazodier Philippe
UP Génétique Bactérienne et Différenciation, Institut Pasteur, 25 rue du Docteur Roux, 75724, Paris Cedex 15, France.
Arch Microbiol. 2006 Feb;184(6):343-52. doi: 10.1007/s00203-005-0051-y. Epub 2005 Nov 25.
ssrA genes encoding tmRNA with transfer and messenger RNA functions are ubiquitous in bacteria. In a process called trans-translation, tmRNA enters a stalled ribosome and allows release of the original mRNA, then tmRNA becomes the template for translation of a short tag that signals for proteolytic degradation. We provide here the first evidences that the tmRNA tagging system (ssrA and cohort smpB) is active in Streptomyces. Transcription of the genes was shown and construction of a genetic probe allowed detection of a tmRNA-tagged peptide. Obtention of ssrA and smpB mutants of Streptomyces lividans showed that the ssrA system is dispensable in Streptomyces. Morphologies of the mutants colonies were similar to the wild type, thus tmRNA-mediated tagging does not seem to have, under conditions used, a significant effect in the Streptomyces differentiation.
编码具有转移和信使RNA功能的tmRNA的ssrA基因在细菌中普遍存在。在一个称为反式翻译的过程中，tmRNA进入停滞的核糖体并使原始mRNA释放，然后tmRNA成为翻译一个短标签的模板，该标签信号用于蛋白水解降解。我们在此提供了首个证据，证明tmRNA标签系统（ssrA和协同的smpB）在链霉菌中具有活性。展示了这些基因的转录情况，并构建了一个基因探针以检测tmRNA标记的肽。获得天蓝色链霉菌的ssrA和smpB突变体表明，ssrA系统在链霉菌中是可有可无的。突变体菌落的形态与野生型相似，因此在所用条件下，tmRNA介导的标签似乎对链霉菌的分化没有显著影响。
