Biomaterial Database

Replication of Mu prophages lacking the central strong gyrase site. 2004

Martin L Pato

Department of Microbiology, University of Colorado Health Sciences Center, 4200 E, 9th Ave., Denver, CO, USA. martin.pato@uchsc.edu

Replication of Mu prophages lacking the central strong gyrase site (SGS) is severely slowed. To study details of the replication of these prophages, an assay was developed for determining the rate and extent of introduction of nicks at the 3'-ends of a Mu prophage, an early step in Mu replicative transposition. The maximal level of end-nicking of a prophage with the SGS, about 70-90% depending upon the host strain, was achieved within about 15 min after induction, whereas at that time less than 5% nicking was observed with a prophage lacking the SGS. The amount of nicking at the end of the SGS(-) prophage increased with time, and approx. 30% nicking of the SGS(-) prophage was achieved by 60 min post-induction. Nicking kinetics were identical at each end of the prophages, and no nicking was observed at the 5'-ends of the prophages, verifying in vivo the earlier results with in vitro systems. To determine if prophage location affects the kinetics of replication, we examined prophages at numerous chromosomal locations. SGS(+) prophages at different chromosomal locations showed essentially identical replication kinetics. SGS(-) prophages showed a range of delays in replication and host lysis. A gradient of delays was apparent, with prophages further from the chromosomal origin of replication, oriC, showing longer delays than ones nearer to oriC. However, there were also exceptions to this overall gradient. Possible explanations for the differences in the delays observed with SGS(-) prophages are discussed.

UI	MeSH Term	Description	Entries
D008242	Lysogeny	The phenomenon by which a temperate phage incorporates itself into the DNA of a bacterial host, establishing a kind of symbiotic relation between PROPHAGE and bacterium which results in the perpetuation of the prophage in all the descendants of the bacterium. Upon induction (VIRUS ACTIVATION) by various agents, such as ultraviolet radiation, the phage is released, which then becomes virulent and lyses the bacterium.	Integration, Prophage,Prophage Integration,Integrations, Prophage,Prophage Integrations
D010583	Bacteriophage mu	A temperate coliphage, in the genus Mu-like viruses, family MYOVIRIDAE, composed of a linear, double-stranded molecule of DNA, which is able to insert itself randomly at any point on the host chromosome. It frequently causes a mutation by interrupting the continuity of the bacterial OPERON at the site of insertion.	Coliphage mu,Enterobacteria phage Mu,Phage mu,mu Phage,mu Phages
D004261	DNA Replication	The process by which a DNA molecule is duplicated.	Autonomous Replication,Replication, Autonomous,Autonomous Replications,DNA Replications,Replication, DNA,Replications, Autonomous,Replications, DNA
D004279	DNA, Viral	Deoxyribonucleic acid that makes up the genetic material of viruses.	Viral DNA
D004926	Escherichia coli	A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.	Alkalescens-Dispar Group,Bacillus coli,Bacterium coli,Bacterium coli commune,Diffusely Adherent Escherichia coli,E coli,EAggEC,Enteroaggregative Escherichia coli,Enterococcus coli,Diffusely Adherent E. coli,Enteroaggregative E. coli,Enteroinvasive E. coli,Enteroinvasive Escherichia coli
D015183	Restriction Mapping	Use of restriction endonucleases to analyze and generate a physical map of genomes, genes, or other segments of DNA.	Endonuclease Mapping, Restriction,Enzyme Mapping, Restriction,Site Mapping, Restriction,Analysis, Restriction Enzyme,Enzyme Analysis, Restriction,Restriction Enzyme Analysis,Analyses, Restriction Enzyme,Endonuclease Mappings, Restriction,Enzyme Analyses, Restriction,Enzyme Mappings, Restriction,Mapping, Restriction,Mapping, Restriction Endonuclease,Mapping, Restriction Enzyme,Mapping, Restriction Site,Mappings, Restriction,Mappings, Restriction Endonuclease,Mappings, Restriction Enzyme,Mappings, Restriction Site,Restriction Endonuclease Mapping,Restriction Endonuclease Mappings,Restriction Enzyme Analyses,Restriction Enzyme Mapping,Restriction Enzyme Mappings,Restriction Mappings,Restriction Site Mapping,Restriction Site Mappings,Site Mappings, Restriction
D016679	Genome, Viral	The complete genetic complement contained in a DNA or RNA molecule in a virus.	Viral Genome,Genomes, Viral,Viral Genomes
D027081	DNA Gyrase	A bacterial DNA topoisomerase II that catalyzes ATP-dependent breakage of both strands of DNA, passage of the unbroken strands through the breaks, and rejoining of the broken strands. Gyrase binds to DNA as a heterotetramer consisting of two A and two B subunits. In the presence of ATP, gyrase is able to convert the relaxed circular DNA duplex into a superhelix. In the absence of ATP, supercoiled DNA is relaxed by DNA gyrase.	DNA Gyrase A Subunit,DNA Gyrase B Subunit,DNA-Gyrase,GyrA Protein,GyrB Protein