RnlB Antitoxin of the Escherichia coli RnlA-RnlB Toxin-Antitoxin Module Requires RNase HI for Inhibition of RnlA Toxin Activity.

ABSTRACT: The Escherichia coli RnlA-RnlB toxin-antitoxin system is related to the anti-phage mechanism. Under normal growth conditions, an RnlA toxin with endoribonuclease activity is inhibited by binding of its cognate RnlB antitoxin. After bacteriophage T4 infection, RnlA is activated by the disappearance of RnlB, resulting in the rapid degradation of T4 mRNAs and consequently no T4 propagation when T4 dmd encoding a phage antitoxin against RnlA is defective. Intriguingly, E. coli RNase HI, which plays a key role in DNA replication, is required for the activation of RnlA and stimulates the RNA cleavage activity of RnlA. Here, we report an additional role of RNase HI in the regulation of RnlA-RnlB system. Both RNase HI and RnlB are associated with NRD (one of three domains of RnlA). The interaction

SUBMITTER: Naka K 

PROVIDER: S-EPMC5308261 | biostudies-literature | 2017 Jan

REPOSITORIES: biostudies-literature