کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
4359380 | 1300503 | 2009 | 8 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Regulation of expression of the tricarballylate utilization operon (tcuABC) of Salmonella enterica Regulation of expression of the tricarballylate utilization operon (tcuABC) of Salmonella enterica](/preview/png/4359380.png)
The tricarballylate utilization locus (tcuRABC) of Salmonella enterica serovar Typhimurium is comprised of a 3-gene operon (tcuABC) that encodes functions that allow this bacterium to use tricarballylate as a source of carbon and energy, and the tcuR gene, which encodes a putative LysR-type transcriptional regulator. In our studies, transcription of the tcuABC operon peaked at mid-log phase, and declined moderately during stationary phase. This pattern was not due to a change in the amount of TcuR in the cell, as tcuR expression did not change under the conditions tested, and TcuR did not control tcuR expression. Tricarballylate was the co-inducer. tcuABC expression was negatively affected by the cAMP receptor protein (Crp). Expression of tcuABC was one order of magnitude higher in a crp mutant strain than in the crp+ strain; derepression of tcuABC expression was also observed in a strain lacking adenylate cyclase (Cya). At present, it is unclear whether the effect of Crp is direct or indirect. Studies with molecular mimics of tricarballylate showed that the co-inducer site restricts binding of structural mimics that contain a hydroxyl group. Two classes of TcuR constitutive variants were isolated. Class I variants responded to tricarballylate, while Class II did not.
Journal: Research in Microbiology - Volume 160, Issue 3, April 2009, Pages 179–186