Activation by TyrR in Escherichia coli K-12 by Interaction between TyrR and the α-Subunit of RNA Polymerase.

ABSTRACT: A novel selection was developed for mutants of the C-terminal domain of RpoA (α-CTD) altered in activation by the TyrR regulatory protein of Escherichia coli K-12. This allowed the identification of an aspartate to asparagine substitution at residue 250 (DN250) as an activation-defective (Act^-) mutation. Amino acid residues known to be close to D250 were altered by in vitro mutagenesis, and the substitutions DR250, RE310, and RD310 were all shown to be defective in activation. None of these mutations caused defects in regulation of the upstream promoter (UP) element. The rpoA mutation DN250 was transferred onto the chromosome to facilitate the isolation of suppressor mutations. The TyrR mutations EK139 and RG119 caused partial suppression of rpoA DN250, and

SUBMITTER: Camakaris H 

PROVIDER: S-EPMC8425403 | biostudies-literature | 2021 Sep

REPOSITORIES: biostudies-literature