Pyr RNA binding to the Bacillus caldolyticus PyrR attenuation protein - characterization and regulation by uridine and guanosine nucleotides.

ABSTRACT: The PyrR protein regulates expression of pyrimidine biosynthetic (pyr) genes in many bacteria. PyrR binds to specific sites in the 5' leader RNA of target operons and favors attenuation of transcription. Filter binding and gel mobility assays were used to characterize the binding of PyrR from Bacillus caldolyticus to RNA sequences (binding loops) from the three attenuation regions of the B. caldolyticus pyr operon. Binding of PyrR to the three binding loops and modulation of RNA binding by nucleotides was similar for all three RNAs. The apparent dissociation constants at 0 degrees C were in the range 0.13-0.87 nm in the absence of effectors; dissociation constants were decreased by three- to 12-fold by uridine nucleotides and increased by 40- to 200-fold by guanosine nucleotides. The bindi

SUBMITTER: Jorgensen CM 

PROVIDER: S-EPMC3232022 | biostudies-literature | 2008 Feb

REPOSITORIES: biostudies-literature