title: Escherichia coli endoribonucleases involved in cleavage of bacteriophage T4 mRNAs.
abstract: The dmd mutant of bacteriophage T4 has a defect in growth because of rapid degradation of late-gene mRNAs, presumably caused by mutant-specific cleavages of RNA. Some such cleavages can occur in an allele-specific manner, depending on the translatability of RNA or the presence of a termination codon. Other cleavages are independent of translation. In the present study, by introducing plasmids carrying various soc alleles, we could detect cleavages of soc RNA in uninfected cells identical to those found in dmd mutant-infected cells. We isolated five Escherichia coli mutant strains in which the dmd mutant was able to grow. One of these strains completely suppressed the dmd mutant-specific cleavages of soc RNA. The loci of the E. coli mutations and the effects of mutations in known RNase-encoding genes suggested that an RNA cleavage activity causing the dmd mutant-specific mRNA degradation is attributable to a novel RNase. In addition, we present evidence that 5'-truncated soc RNA, a stable form in T4-infected cells regardless of the presence of a dmd mutation, is generated by RNase E.
authors.affiliation: Department of Biology, Graduate School of Science, Osaka University, 1-16 Machikaneyama-cho, Toyonaka, Osaka 560-0043, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Otsuka
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ueno
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Yonesaki
mesh_terms: D017122:Bacteriophage T4 / Q000235:genetics*; D004722:Endoribonucleases / Q000502:physiology*; D004926:Escherichia coli / Q000201:enzymology*; D029968:Escherichia coli Proteins; D009154:Mutation; D012333:RNA, Messenger / Q000378:metabolism*; D012367:RNA, Viral / Q000378:metabolism*; D014157:Transcription Factors / Q000502:physiology
chemical_list: D029968:Escherichia coli Proteins; C499695:IscR protein, E coli; D012333:RNA, Messenger; D012367:RNA, Viral; D014157:Transcription Factors; D004722:Endoribonucleases; C022537:ribonuclease E