Half-Site DNA sequence and spacing length contributions to PrrA binding to PrrA site 2 of RSP3361 in Rhodobacter sphaeroides 2.4.1.

ABSTRACT: The consensus DNA binding sequence for PrrA, a global regulator in Rhodobacter sphaeroides 2.4.1, is poorly defined. We have performed mutational analysis of PrrA site 2, of the RSP3361 gene, to which PrrA binds in vitro (J. M. Eraso and S. Kaplan, J. Bacteriol. 191:4341-4352, 2009), to further define the consensus sequence for DNA binding. Two half-sites of equal length, containing 6 nucleotides each, were required for PrrA binding to this DNA sequence. Systematic nucleotide substitutions in both inverted half-sites led to a decrease in binding affinity of phosphorylated PrrA in vitro, the level of which was dependent on the substitution. The reduced binding affinities were confirmed by competition experiments and led to proportional decreases in the expression of lacZ transcriptional fus

SUBMITTER: Eraso JM 

PROVIDER: S-EPMC2698480 | biostudies-literature | 2009 Jul

REPOSITORIES: biostudies-literature