title: [Bacteriophage MS2 mutants with disrupted phage replicase repressor activity].
abstract: A number of ts-mutants with altered characteristics of RNA synthesis in non-suppressor cells at elevated temperatures have been obtained after HNO2-treatment of phage MS2am623 (amber mutation in site 50). The mutant ts130 is studied in detail: its peak of RNA synthesis is displaced 10 min. later and the total amount of RNA is reduced in 5-10 times. No RNA synthesis is observed in ts130-infected cell at 46 degrees C. Changes in the character of RNA synthesis are accompanied by the over-production of phage subunit of replicase: at 42 degrees C the replicase/RNA ratio in ts130 is 20 times higher than that of the original phage MS2am623. It is assumed that there is a decrease in the activity of replicase--RNA repressor complex in ts130 resulting in the loss of replicase control over its own synthesis while the control of coat protein synthesis remains unaffected.
mesh_terms: D003090:Coliphages / Q000201:enzymology / Q000235:genetics*; D004926:Escherichia coli / Q000378:metabolism; D009154:Mutation; D014176:Protein Biosynthesis; D012316:RNA Nucleotidyltransferases / Q000235:genetics*; D012317:RNA Phages / Q000201:enzymology / Q000235:genetics*; D012367:RNA, Viral / Q000096:biosynthesis / Q000235:genetics*; D012324:RNA-Dependent RNA Polymerase / Q000235:genetics*; D012097:Repressor Proteins / Q000032:analysis*; D013696:Temperature; D014157:Transcription Factors / Q000032:analysis*; D014764:Viral Proteins / Q000096:biosynthesis
chemical_list: D012367:RNA, Viral; D012097:Repressor Proteins; D014157:Transcription Factors; D014764:Viral Proteins; D012316:RNA Nucleotidyltransferases; D012324:RNA-Dependent RNA Polymerase
vernacular_title: Mutanty bakteriofaga MS2 a narusheniem repressornoĭ aktivnosti fagovoĭ replicazy.