tRNA genes and pathogenicity islands: influence on virulence and metabolic properties of uropathogenic Escherichia coli

作者：Angelika Ritter, Gabriele Blum, Levente Emödy, Mónika Kerényi, August Böck, Bernhard Neuhieri, Wolfgang Rabsch, Flemming Scheutz, Jörg Hinrich Hacker · 发表于：Molecular Microbiology · 年份：1995 · DOI：10.1111/j.1365-2958.1995.mmi_17010109.x · 被引用次数：101 · 研究领域：Escherichia coli research studies、Antibiotic Resistance in Bacteria、Enterobacteriaceae and Cronobacter Research

The uropathogenic Escherichia coli strain 536 (O6:K15:H31) carries two unstable DNA regions on its chromosome which were termed pathogenicity islands (Pais). Both pathogenicity islands, Pai I and Pai II, are incorporated into tRNA specific loci: Pai I is located in the tRNA gene for selenocysteine (selC), and Pai II is integrated in the leucine-specific tRNA locus leuX. Mutant strain 536-21 has lost the two pathogenicity islands together with the intact tRNA genes. While 536 is a virulent strain, 536-21 has lost a number of properties, including in vivo virulence. In previous publications we reported that the genes coding for two haemolysins (hly I, hly II) and P-related fimbria (prf) are located on the Pais. In this paper, we demonstrate that the expression of other gene products influencing metabolic properties in addition to in vivo virulence are strongly dependent on the intact tRNA loci selC and leuX. In order to determine the influence of the two tRNAs on the expression of these properties, the genes selC and leuX were cloned from the genome of strain 536 and then introduced into the mutant 536-21. Our results clearly show that the seleno-cysteine-specific tRNA (tRNA(Sec)) directly influences the ability of the bacteria to grow under anaerobic conditions, because selenocysteine is part of the enzyme formate dehydrogenase (FDH) which is involved in mixed acid fermentation. The rare leucine-specific tRNA5(Leu), encoded by leuX, influences a number if properties including ...