Serine-Threonine Kinases Encoded by Split hipA Homologs Inhibit Tryptophanyl-tRNA Synthetase.

ABSTRACT: Type II toxin-antitoxin (TA) modules encode a stable toxin that inhibits cell growth and an unstable protein antitoxin that neutralizes the toxin by direct protein-protein contact. hipBA of Escherichia coli strain K-12 codes for HipA, a serine-threonine kinase that phosphorylates and inhibits glutamyl-tRNA synthetase. Induction of hipA inhibits charging of glutamyl-tRNA that, in turn, inhibits translation and induces RelA-dependent (p)ppGpp synthesis and multidrug tolerance. Here, we describe the discovery of a three-component TA gene family that encodes toxin HipT, which exhibits sequence similarity with the C-terminal part of HipA. A genetic screening revealed that trpS in high copy numbers suppresses HipT-mediated growth inhibition. We show that HipT of E.

SUBMITTER: Vang Nielsen S 

PROVIDER: S-EPMC6581861 | biostudies-literature | 2019 Jun

REPOSITORIES: biostudies-literature