title: Novobiocin blocks the shutoff of SPO1 early transcription.
abstract: Novobiocin, an inhibitor of bacterial DNA gyrase strongly impairs the development of bacteriophage SPOl. DNA replication seems to be the primary target for the antibiotic in this system, but viral-coded transcription is also affected in several aspects: (a) The level of phage transcription is diminished; (b) the shutoff of the synthesis of early RNA classes is inhibited; (c) RNAs of late class are not synthesized. This last effect is a consequence of the coupling between transcription and replication. The other two results could be taken as an indication that the appropriate secondary structure of the parental phage DNA is a requisite for the recognition of promoters. The introduction of negative turns by DNA gyrase seems to make early genes unavailable for transcription.
mesh_terms: D001412:Bacillus subtilis / Q000378:metabolism; D001435:Bacteriophages / Q000235:genetics*; D004261:DNA Replication / Q000187:drug effects; D004279:DNA, Viral / Q000096:biosynthesis; D009675:Novobiocin / Q000494:pharmacology*; D009693:Nucleic Acid Hybridization; D012333:RNA, Messenger / Q000096:biosynthesis; D012367:RNA, Viral / Q000096:biosynthesis; D013997:Time Factors; D059005:Topoisomerase II Inhibitors; D014158:Transcription, Genetic / Q000187:drug effects*
chemical_list: D004279:DNA, Viral; D012333:RNA, Messenger; D012367:RNA, Viral; D059005:Topoisomerase II Inhibitors; D009675:Novobiocin