title: E.coli cell-cycle regulation by bacteriophage lambda.
abstract: We re-examined the old but surprising claim of Kourilsky and Knapp that transient expression of genes located downstream of the p(L) promoter of bacteriophage lambda can induce cell-cycle synchrony in a population of Escherichia coli cells. Although we were unable to reproduce a lasting synchrony, a cessation of division, followed by one or two fairly synchronous cell divisions was observed. This line up of the cell cycle was found to be due to two genetically separable events: a temporary block of cell division and, at the same time, a block to the initiation of new rounds of DNA replication. These blocks then release after about one mass doubling so that chromosome replication and cell division occur during a short time interval in all the cells in the population. The cell division block is a result of the transient expression of the lambda kil gene. The block to initiation of DNA replication requires a region that we term bin (blocks initiation) immediately upstream of the xis gene. The region consists of ea22 and ea8.5 and two small open reading frames (ORFs) that flank them. Deletion-substitution mutagenesis suggests that all four ORFs may be required for the initiation block. The ability of the phage to modify two aspects of the host cell cycle presumably reflects a stratagem that provides the phage with an advantage for lysogeny or lytic growth.
authors.affiliation: Gene Regulation and Chromosome Biology Laboratory, National Cancer Institute, NCI-FCRDC, PO Box B, Building 539, Frederick, MD 21702-1201, USA.
authors.forename: Kirill
authors.initials: K
authors.lastname: Sergueev
authors.forename: Donald
authors.initials: D
authors.lastname: Court
authors.forename: Lucretia
authors.initials: L
authors.lastname: Reaves
authors.forename: Stuart
authors.initials: S
authors.lastname: Austin
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D010582:Bacteriophage lambda / Q000502:physiology*; D002453:Cell Cycle / Q000502:physiology*; D002455:Cell Division; D002876:Chromosomes, Bacterial; D018387:Codon, Initiator / Q000235:genetics; D017931:DNA Primers / Q000737:chemistry; D004261:DNA Replication; D004268:DNA-Binding Proteins; D004926:Escherichia coli / Q000166:cytology*; D029968:Escherichia coli Proteins; D005144:F Factor; D017353:Gene Deletion; D015870:Gene Expression; D008242:Lysogeny; D016366:Open Reading Frames; D017354:Point Mutation; D011995:Recombination, Genetic; D018741:Replication Origin; D012097:Repressor Proteins; D014764:Viral Proteins; D054334:Viral Regulatory and Accessory Proteins
chemical_list: D001426:Bacterial Proteins; D018387:Codon, Initiator; D017931:DNA Primers; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D012097:Repressor Proteins; D014764:Viral Proteins; D054334:Viral Regulatory and Accessory Proteins; C065410:gam protein, Coliphage; C069003:kil protein, E coli; C016649:phage repressor proteins