title: Consequences of RNase E scarcity in Escherichia coli.
abstract: The endoribonuclease RNase E plays an important role in RNA processing and degradation in Escherichia coli. The construction of an E. coli strain in which the cellular concentration of RNase E can be precisely controlled has made it possible to examine and quantify the effect of RNase E scarcity on RNA decay, gene regulation and cell growth. These studies show that RNase E participates in a step in the degradation of its RNA substrates that is partially or fully rate-determining. Our data also indicate that E. coli growth requires a cellular RNase E concentration at least 10-20% of normal and that the feedback mechanism that limits overproduction of RNase E is also able to increase its synthesis when its concentration drops below normal. The magnitude of the in-crease in RNA longevity under conditions of RNase E scarcity may be limited by an alternative pathway for RNA degradation. Additional experiments show that RNase E is a stable protein in E. coli. No other E. coli gene product, when either mutated or cloned on a multicopy plasmid, seems to be capable of compensating for an inadequate supply of this essential protein.
authors.affiliation: Skirball Institute of Biomolecular Medicine and Department of Microbiology, New York University School of Medicine, 540 First Avenue, New York, NY 10016, USA.
authors.forename: Chaitanya
authors.initials: C
authors.lastname: Jain
authors.forename: Atilio
authors.initials: A
authors.lastname: Deana
authors.forename: Joel G
authors.initials: JG
authors.lastname: Belasco
mesh_terms: D002455:Cell Division; D004722:Endoribonucleases / Q000235:genetics / Q000378:metabolism*; D004795:Enzyme Stability; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D005798:Genes, Bacterial; D006706:Homeostasis; D007544:Isopropyl Thiogalactoside / Q000494:pharmacology; D012329:RNA, Bacterial / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D012329:RNA, Bacterial; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D007544:Isopropyl Thiogalactoside; D004722:Endoribonucleases; C022537:ribonuclease E