Autoinducer binding by the quorum-sensing regulator TraR increases affinity for target promoters in vitro and decreases TraR turnover rates in whole cells.
نویسندگان
چکیده
TraR is an Agrobacterium transcriptional regulator whose activity requires the pheromone N-3-oxooctanoyl-L-homoserine lactone. TraR was purified as a complex with the pheromone and contained one pheromone molecule per protein monomer. TraR-pheromone complexes bound to a single DNA site and activated two promoters that flank this site. Promoter expression was elevated 30-fold by using a supercoiled template. Pheromone binding increased the affinity of TraR for this binding site. Pheromone also increased TraR abundance in vivo by causing a 20-fold decrease in TraR turnover rates.
منابع مشابه
Amino-terminal protein fusions to the TraR quorum-sensing transcription factor enhance protein stability and autoinducer-independent activity.
TraR of Agrobacterium tumefaciens is a member of the LuxR family of quorum-sensing transcription factors and regulates genes required for conjugation and vegetative replication of the tumor-inducing (Ti) plasmid in the presence of the autoinducer 3-oxooctanoyl-homoserine lactone (OOHL). In the absence of OOHL, TraR is rapidly destroyed by proteolysis, suggesting that this ligand is required for...
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ورودعنوان ژورنال:
- Proceedings of the National Academy of Sciences of the United States of America
دوره 96 9 شماره
صفحات -
تاریخ انتشار 1999