2026-04-13T07:38:07Zhttps://recercat.cat/oai/request

oai:recercat.cat:2445/1735222025-12-04T22:52:07Zcom_2072_1057col_2072_478825col_2072_478916col_2072_478917

00925njm 22002777a 4500 dc Gibert, Marta author Paytubi Casabona, Sònia author Madrid Xufré, Cristina author Balsalobre Parra, Carlos author 2021-01-29T12:05:12Z 2021-01-29T12:05:12Z 2020-07-10 2021-01-29T12:05:12Z Conjugation of R27 plasmid is thermoregulated, being promoted at 25°C and repressed at 37°C. Previous studies identified plasmid-encoded regulators, HtdA, TrhR and TrhY, that control expression of conjugation-related genes (tra). Moreover, the nucleoid-associated protein H-NS represses conjugation at non-permissive temperature. A transcriptomic approach has been used to characterize the effect of temperature on the expression of the 205 R27 genes. Many of the 35 tra genes, directly involved in plasmid-conjugation, were upregulated at 25°C. However, the majority of the non-tra R27 genes many of them with unknown function were more actively expressed at 37°C. The role of HtdA, a regulator that causes repression of the R27 conjugation by counteracting TrhR/TrhY mediated activation of tra genes, has been investigated. Most of the R27 genes are severely derepressed at 25°C in an htdA mutant, suggesting that HtdA is involved also in the repression of R27 genes other than the tra genes. Interestingly, the effect of htdA mutation was abolished at non-permissive temperature, indicating that the HtdA-TrhR/TrhY regulatory circuit mediates the environmental regulation of R27 gene expression. The role of H-NS in the proposed model is discussed. Plasmidis Expressió gènica Plasmids Gene expression Temperature Dependent Control of the R27 Conjugative Plasmid Genes