Autoregulation of luxR: the Vibrio harveyi lux-operon activator functions as a repressor
| Autor: | Edward A. Meighen, Carol M. Miyamoto, Jaidip Chatterjee |
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| Rok vydání: | 1996 |
| Předmět: |
Operon
Recombinant Fusion Proteins Repressor Biology Microbiology Gene product Bacterial Proteins Binding site Promoter Regions Genetic Molecular Biology Psychological repression Vibrio Genetics Binding Sites Vibrio harveyi Activator (genetics) food and beverages DNA-Directed RNA Polymerases Gene Expression Regulation Bacterial biochemical phenomena metabolism and nutrition biology.organism_classification Repressor Proteins Open reading frame Trans-Activators bacteria |
| Zdroj: | Molecular Microbiology. 20:415-425 |
| ISSN: | 1365-2958 0950-382X |
| Popis: | Mobility-shift assays have been used to demonstrate that the activator of the Vibrio harveyi lux operon, LuxR, binds independently, and with similar affinity, to two sites upstream of its own open reading frame. One site was located between 52 and 107 bp upstream of, and the other site in a region 25 bp downstream of, the transcriptional start site. The luxR promoter, in a transcriptional fusion with the chloramphenicol acetyl transferase (cat) gene, could readily be expressed in Escherichia coli as well as V. harveyi in the absence of LuxR. In both species, the presence of the luxR gene product resulted in repression of luxR promotion. These results show that LuxR directly regulates its own expression by functioning as an autorepressor. A mechanism for this repression is suggested by evidence showing that LuxR has a negative effect on RNA polymerase binding to the luxR promoter. In light of the fact that LuxR is also part of a regulatory family of repressors, the mechanism by which LuxR functions as a transcriptional activator of the lux operon has been re-examined. |
| Databáze: | OpenAIRE |
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