Thermoregulation in Yersinia enterocolitica is coincident with changes in DNA supercoiling.

摘要: Yersinia enterocolitica is a facultative intracellular parasite, displaying the ability to grow saprophytically or invade and persist intracellularly in mammalian reticuloendothelial system. The transition between such diverse environments requires co-ordinated regulation of specific sets genes on both chromosome virulence plasmid. Temperature has profound pleiotropic effect gene expression phenotypically promotes alterations cell morphology, outer-membrane protein synthesis, urease production, lipopolysaccharide motility, synthesis involved invasion eukaryotic host cells. By examining thermoregulated flagella biosynthesis, we have determined that motility repressed at 25 degrees C (permissive temperature) with subinhibitory concentrations novobiocin. These conditions also induce suggesting novobiocin addition simulates, least partially, high-temperature environment. Furthermore, temperature-shift experiments, using Y. containing pACYC184 as reporter plasmid, indicate thermo-induced DNA supercoiling coincide temperature-induced phenotypic changes. A class putative gyrase mutant (novobiocin resistant) likewise demonstrates 37 phenotype when cultured C; it non-motile, negative, calcium growth dependent, positive for Yop expression. results support model implicating topology contributing factor thermoregulation.