Biomaterial Database

Role of the bacteriophage lambda exo-xis region in the virus development. 2008

J M Łoś, and M Łoś, and A Wegrzyn, and G Wegrzyn

Department of Molecular Biology, University of Gdańsk, 80-822, Gdańsk, Poland.

Various processes of bacteriophage lambda development in Escherichia coli cells bearing either the whole lambda exo-xis region (with truncated, thus nonfunctional, exo and xis genes) or particular genes from this region were investigated. The presence of either the exo-xis region or the ea8.5 gene on a plasmid resulted in formation of fuzzy plaques by infecting phage. Both efficiency of plating and efficiency of lysogenization were decreased in such hosts. On the other hand, neither the efficiency of adsorption nor intracellular lytic development of the infecting phage (measured in one-step-growth experiments) was affected while significantly more host cells survived the infection, when containing the exo-xis region. Although no effects of the exo-xis region on the activity of the p (L) promoter was detected, this region contributed to a decreased transcription from the cII-stimulated promoters p (I), p (aQ) and p (E). These results, together with the results of measurement of efficiency of plating of phages bearing mutations in cI, cII and cIII genes on hosts containing the exo-xis region, strongly suggest that genes from this region (especially ea8.5) are involved in the regulation of bacteriophage lambda development at the stage of the lysis-vs.-lysogenization decision.

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
D009154	Mutation	Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.	Mutations
D010582	Bacteriophage lambda	A temperate inducible phage and type species of the genus lambda-like viruses, in the family SIPHOVIRIDAE. Its natural host is E. coli K12. Its VIRION contains linear double-stranded DNA with single-stranded 12-base 5' sticky ends. The DNA circularizes on infection.	Coliphage lambda,Enterobacteria phage lambda,Phage lambda,lambda Phage
D010948	Viral Plaque Assay	Method for measuring viral infectivity and multiplication in CULTURED CELLS. Clear lysed areas or plaques develop as the VIRAL PARTICLES are released from the infected cells during incubation. With some VIRUSES, the cells are killed by a cytopathic effect; with others, the infected cells are not killed but can be detected by their hemadsorptive ability. Sometimes the plaque cells contain VIRAL ANTIGENS which can be measured by IMMUNOFLUORESCENCE.	Bacteriophage Plaque Assay,Assay, Bacteriophage Plaque,Assay, Viral Plaque,Assays, Bacteriophage Plaque,Assays, Viral Plaque,Bacteriophage Plaque Assays,Plaque Assay, Bacteriophage,Plaque Assay, Viral,Plaque Assays, Bacteriophage,Plaque Assays, Viral,Viral Plaque Assays
D004254	DNA Nucleotidyltransferases	Enzymes that catalyze the incorporation of deoxyribonucleotides into a chain of DNA. EC 2.7.7.-.	Nucleotidyltransferases, 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
D005090	Exodeoxyribonucleases	A family of enzymes that catalyze the exonucleolytic cleavage of DNA. It includes members of the class EC 3.1.11 that produce 5'-phosphomonoesters as cleavage products.	DNA Exonucleases,Exonucleases, DNA
D001433	Bacteriolysis	Rupture of bacterial cells due to mechanical force, chemical action, or the lytic growth of BACTERIOPHAGES.	Bacteriolyses
D014764	Viral Proteins	Proteins found in any species of virus.	Gene Products, Viral,Viral Gene Products,Viral Gene Proteins,Viral Protein,Protein, Viral,Proteins, Viral
D015967	Gene Expression Regulation, Viral	Any of the processes by which cytoplasmic factors influence the differential control of gene action in viruses.	Regulation of Gene Expression, Viral,Viral Gene Expression Regulation,Regulation, Gene Expression, Viral