RRC ID 35648
著者 Naka K, Koga M, Yonesaki T, Otsuka Y.
タイトル RNase HI stimulates the activity of RnlA toxin in Escherichia coli.
ジャーナル Mol Microbiol
Abstract A type II toxin-antitoxin system in Escherichia coli, rnlA-rnlB, functions as an anti-phage mechanism. RnlA is a toxin with an endoribonuclease activity and the cognate RnlB inhibits RnlA toxicity in E. coli cells. 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 is defective: Dmd is an antitoxin against RnlA for promoting own propagation. Previous studies suggested that the activation of RnlA after T4 infection was regulated by multiple components. Here, we provide the evidence that RNase HI is an essential factor for activation of RnlA. The dmd mutant phage could grow on ΔrnhA (encoding RNase HI) cells, in which RnlA-mediated mRNA cleavage activity was defective. RNase HI bound to RnlA in vivo and enhanced the RNA cleavage activity of RnlA in vitro. In addition, ectopic expression of RnlA in ΔrnlAB ΔrnhA cells has less effect on cell toxicity and RnlA-mediated mRNA degradation than in ΔrnlAB cells. This is the first example of a direct factor for activation of a toxin.
巻・号 91(3)
ページ 596-605
公開日 2014-2-1
DOI 10.1111/mmi.12479
PMID 24308852
MeSH Bacteriophage T4 / growth & development Escherichia coli / enzymology* Escherichia coli / genetics Escherichia coli Proteins / toxicity* Gene Deletion Ribonuclease H / genetics Ribonuclease H / metabolism*
IF 3.418
引用数 7
WOS 分野 BIOCHEMISTRY & MOLECULAR BIOLOGY MICROBIOLOGY
リソース情報
原核生物(大腸菌) ME5479(MH1) JW0204-KC JW0178-KC JW2669-KC