Acetylation regulates the stability of a bacterial protein: growth stage-dependent modification of RNase R.

ABSTRACT: RNase R, an Escherichia coli exoribonuclease important for degradation of structured RNAs, increases 3- to 10-fold under certain stress conditions, due to an increased half-life for this usually unstable protein. Components of the trans-translation machinery, tmRNA, and its associated protein, SmpB, are essential for RNase R instability. However, it is not understood why exponential phase RNase R is unstable or how it becomes stabilized in stationary phase. Here, we show that these phenomena are regulated by acetylation catalyzed by YfiQ protein. One residue, Lys544, is acetylated in exponential phase RNase R, but not in the stationary phase protein, resulting in tighter binding of tmRNA-SmpB to the C-terminal region of exponential phase RNase R and subsequent proteolytic degradation. Remo

SUBMITTER: Liang W 

PROVIDER: S-EPMC3191462 | biostudies-literature | 2011 Oct

REPOSITORIES: biostudies-literature