Structure and regulation of the lytic replicon of phage P1

摘要: Three replicons, R, L and P1dR, have been previously identified in bacteriophage P1, but only the R (or plasmid) replicon has functionally structurally characterized. Evidence is provided here that L-replicon principal used for DNA replication during lytic cycle. The (exclusive of its promoter) shown to be contained within a 1093-base-pair segment includes 281-codon open reading frame, designated repL. function requires transcription direction should generate translatable repL message. This normally under control phage c1 repressor, deletion places functional alternative can constructed. sequence surrounding regions was established. sequenced region contains c4 ant genes hitherto unidentified gene, kilA, which immediately upstream controlled by c1-regulated promoter. kilA gene non-essential both development whereas probably encodes an essential protein.