Structure of the nucleotide complex of PyrR, the pyr attenuation protein from Bacillus caldolyticus, suggests dual regulation by pyrimidine and purine nucleotides.

ABSTRACT: PyrR is a protein that regulates the expression of genes and operons of pyrimidine nucleotide biosynthesis (pyr genes) in many bacteria. PyrR acts by binding to specific sequences on pyr mRNA and causing transcriptional attenuation when intracellular levels of uridine nucleotides are elevated. PyrR from Bacillus subtilis has been purified and extensively studied. In this work, we describe the purification to homogeneity and characterization of recombinant PyrR from the thermophile Bacillus caldolyticus and the crystal structures of unliganded PyrR and a PyrR-nucleotide complex. The B. caldolyticus pyrR gene was previously shown to restore normal regulation of the B. subtilis pyr operon in a pyrR deletion mutant. Like B. subtilis PyrR, B. caldolyticus PyrR catalyzes the uracil phosphoribosy

SUBMITTER: Chander P 

PROVIDER: S-EPMC1064020 | biostudies-literature | 2005 Mar

REPOSITORIES: biostudies-literature