The use of oriC-dependent phage infection to characterize the ultra violet (UV)-induced inhibition of initiation of DNA replication in Escherichia coli.
The oriC transducing phage lambda poriCc is a pseudovirulent phage capable of forming plaques on a lambda lysogen. This phenotype is dependent upon the presence of the oriC insert. The ability of lambda poriCc to form plaques on a lambda lysogen represents a potential phage assay system for studying aspects of oriC function. In the present study we establish that lambda poriCc infection of a lambda lysogen is a legitimate assay for oriC function. We use this assay to confirm the previously reported observation that initiation of DNA replication from oriC is transiently inhibited in a ultra violet (UV) irradiated cell at doses greater than 60 J/m2. We further demonstrate using this assay that the UV induced inhibition of initiation of DNA replication from oriC is not a SOS function nor a heat shock function. In the course of these studies, we found that lambda poriCc infection of a non-lysogenic cell is extremely sensitive to pre-irradiation of the Escherichia coli host. We postulate that the sensitivity of lambda poriCc replication to host cell pre-irradiation reflects in some way the transient inhibition of initiation of DNA replication from oriC following UV irradiation.
Coates
N J
NJ
Department of Biochemistry, University of Adelaide, Australia.
Dibbens
J A
JA
Moffat
K G
KG
Egan
J B
JB
D010582:Bacteriophage lambda / Q000235:genetics / Q000528:radiation effects; D004261:DNA Replication / Q000502:physiology* / Q000528:radiation effects*; D004268:DNA-Binding Proteins / Q000502:physiology* / Q000528:radiation effects; D004926:Escherichia coli / Q000235:genetics / Q000528:radiation effects*; D006360:Heat-Shock Proteins / Q000502:physiology; D008565:Membrane Proteins / Q000502:physiology; D051738:Origin Recognition Complex; D020664:Son of Sevenless Proteins; D013997:Time Factors; D014466:Ultraviolet Rays; D014764:Viral Proteins / Q000502:physiology* / Q000528:radiation effects
D004268:DNA-Binding Proteins; D006360:Heat-Shock Proteins; D008565:Membrane Proteins; C114650:OriC chromosomal replication origin; D051738:Origin Recognition Complex; D020664:Son of Sevenless Proteins; D014764:Viral Proteins