The Rhizobium etli sigma70 (SigA) factor recognizes a lax consensus promoter.

ABSTRACT: A collection of Rhizobium etli promoters was isolated from a genomic DNA library constructed in the promoter-trap vector pBBMCS53, by their ability to drive the expression of a gusA reporter gene. Thirty-seven clones were selected, and their transcriptional start-sites were determined. The upstream sequence of these 37 start-sites, and the sequences of seven previously identified promoters were compared. On the basis of sequence conservation and mutational analysis, a consensus sequence CTTGACN16-23TATNNT was obtained. In this consensus sequence, nine on of twelve bases are identical to the canonical Escherichia coli sigma70 promoter, however the R.etli promoters only contain 6.4 conserved bases on average. We show that the R.etli sigma factor SigA recognizes all R.etli promoters studied i

SUBMITTER: Ramirez-Romero MA 

PROVIDER: S-EPMC1401509 | biostudies-literature | 2006

REPOSITORIES: biostudies-literature