The regulation of integrative recombination by the b2 region and the cii gene of bacteriophage lambda. Gussin department of zoology, university of iowa, iowa city, iowa 52242 manuscript received july 1,1982 revised copy accepted august 5,1982 abstract complementation tests among previously isolated rex mutants of bacterio. Bacteriophage vectors have potential as gene transfer and vaccine delivery vectors because of their low cost, safety and physical stability. The rex gene of bacteriophage h is really two genes karen matz, margaret schmandt, and gary n. Infection by phage produces many progeny and breaks open lyses the host bacterium lysogeny.
The 0, control system of bacteriophage lambda cbbp lund. Integration host factor assembly at the cohesive end site. Therex gene product excludes phage t4 ri mutants from x lysogens. In vivo gene delivery and expression by bacteriophage. Transcriptional regulation of bacteriophage lambda. Proceedings of the national academy of sciences 2008, 105 15, 58275832. Sitespecific enthalpic regulation of dna transcription at. This gene is situated between the phage attachment site, attp, and the repressor c gene, and is cotranscribed with c from the pc promoter, towards attp.
Implications for viral dna packaging and bacterial gene regulation saurarshi j. The lysislysogeny decision of bacteriophage lambda. We have tested the effects of a hima mutation on the establishment and maintenance of. Pdf regulation of bacteriophage lambda dna replication. Infection by phage t4 initiates profound changes in cellular metabolism, directed in large part towards an increase in the destruction of host dna and increase of phage dna synthesis. Nonessential genes have been identified by isolation of deletion or substitution mutations.
Purification of bacteriophage lambda repressor sciencedirect. When lambda exists as a prophage, its dna is integrated into the host genome and most of its gene expression is repressed. Regulation of int gene expression in bacteriophage p2. Downstream regulation of int gene expression by the b2 region in phage lambda.
A lambda insertion type cdna cloning vector, lambda zap, has been constructed. Values for all interaction parameters of the model have been. When synthesis is complete, the bacterial host cell is lysed and the new phages are released into the. Regulation of gene expression entails a broad range of mechanisms that are used by cells to develop or diminish the production of specific gene products protein or rna, and is informally termed.
Received 15 december 1981 the int gene of bacteriophage lambda can be. Thus, bacteriophage can be viewed as model systems for animal cell viruses. The functional halflife of the phage n gene product, measured by complementation, is increased about 5fold in ion mutant strains, from 2 min to 10 min. The chemical halflife of n protein, determined by its disappearance on polyacrylamide gels following pulsechase labeling, increases about three. Posttranscriptional control of bacteriophage lambda gene. Learn vocabulary, terms, and more with flashcards, games, and other study tools.
A new look at bacteriophage lambda genetic networks f les sequences cos du bacteriophage. The excision process eliminates the need to subclone dna inserts from the lambda phage into a plasmid by restriction digestion and ligation. A statistical thermodynamic model has been developed to account for the cooperative interactions of the bacteriophage lambda repressor with the lambda right operator. Transcriptional regulation in bacteriophage lambda three basic phenomena were discovered. Knowledgebased simulation of genetic regulation in bacteriophage lambda. Previous experiments have shown that the hima gene of e.
Quantitative model for gene regulation by lambda phage. Secondary mutants, selected for growth on reca, lie within the immunity region to the right of gene ci and appear identical to the cro mutants of eisen et al. Promoter for transcription from the int gene under positive regulation by cii and. Temperate phage reside in the host genome and do not kill the host, whereas lytic phage cause lysis of their hosts when they infect bacteria. Dna looping can enhance lysogenic ci transcription in phage lambda. Measuring a gene regulation function grf in individual e. Operon will be used here for a group of linked genes whose transcription requires the availability in cis of a common promoter. Knowledgebased simulation of genetic regulation in. Toxin production by corynebacterium diphtheriae is mediated by a gene carried by a beta phage. Transcription regulation via effects on rna polymerases exercises 18.
Autogenous regulation of the rega gene of bacteriophage t4. Infection by phage t4 initiates profound changes in cellular metabolism, directed in large part towards an increase in the destruction of host dna and increase of. Lysis of bacterial cell envelope and release of progeny phage. Guarneros g, galindo jm 1979 the regulation of integrative recombination by the b2 region and the cii gene of bacteriophage 2. Historically, they were used to define gene structure and gene regulation. In the first moments of infection, lambda makes a decision either to proceed with lysis.
Gene regulation in bacteria and bacteriophages flashcards. Transcriptional regulation in bacteriophage lambda. There are three key features, which characterize the network. Switches in bacteriophage lambda development amos b. Sanyal, tengchieh yang, and carlos enrique catalano department of medicinal chemistry, school of pharmacy, university of washington, h172 health sciences building, box 357610, seattle, washington 98195, united states s supporting. First, after infection of the host bacterium, a decision between lytic or lysogenic development is made that is dependent upon environmental signals and the number of infecting phages per cell.
The tof gene product also known as cro orfed reduces transcription of the ci gene and of the plscripton. However, bacteriophage research did not lead the genomics revolution, which is clearly dominated by bacterial genomics. Regulation of gene expression in bacteria and phage. Switches in bacteriophage lambda development annual. Termination of transcription most likely occurs in the regions between genes nand ciii, between genes tof and 0, and between genes p and q. The contribution of bacteriophage lambda to gene control research is far from over. Oppenheimf, slkan gottesman and max gottekman biochemical genetics section, laboratory of molecular biology national cancer institute, national institutes of health bethesda, md 20205, u. Recently, the lambda gene expression profile has also been investigated systematically. We therefore performed experiments to examine phage. Pdf on jan 1, 1968, m h green and others published regulation of bacteriophage lambda dna replication find, read and cite all the research you need on researchgate. Regulation of gene expression in bacteriophage lambda. Expression profiling via novel multiplex assay allows rapid assessment of gene regulation in defined signalling. Values for all interaction parameters of the model have been evaluated at 37 degrees c, 0. Bacteriophage means to eat bacteria, and are called so because.
Regulation the expression gene bacteriophage lambda. Lambda consists of two types of life cycles, the lytic and lysogenic. Derepression of translation yumei liang, rongxuan wei, tien hsu, charlene alford, myra dawson and jim karam department of biochemistry and molecular biology, medical university of south carolina, charleston, south carolina 29425 manuscript received january 15, 1988. Bacteriophage phage are obligate intracellular parasites that multiply inside bacteria by making use of some or all of the host biosynthetic machinery i. Spherical phages with single stranded dna such as phix174. Introduction to bioinformatics gene regulation and. After infection, the phage dna integrates into the host genome and resides there passively no progeny no lysis of the host can subsequently lyse lysogeny. Infection by phage t4 initiates profound changes in cellular metabolism, directed in large part towards an increase in the destruction of host dna and. In order to study in detail the looping of dna mediated by the protein, tagfree repressor and a lossofcooperativity mutant were expressed in li and purified by 1 ammonium sulfate fractionation, 2 anionexchange chromatography and 3 heparin affinity. The int gene of bacteriophage p2 is the only viral gene necessary for the integration of p2 into the escherichia coli host chromosome.
A revised model of the lambda genetic switch includes extra cooperativity through octamerization of the ci repressor protein, mediated by longrange dna looping. The wild type of this virus has a temperate life cycle that allows it to either reside within the genome of its host through lysogeny or enter into a lytic. Bacteriophage lambda repressor controls the lysogenylytic growth switch after infection of e. Request pdf revisited gene regulation in bacteriophage. Also the first genome to be sequenced was a bacteriophage. Most lambda genes are under the control, directly or indirectly, of the pr and pl promoters pl is similar to pr, but the promoter itself is not directly involved in ci regulation.
Scott meyers, peter friedland, knowledgebased simulation of genetic regulation in bacteriophage lambda, nucleic acids research, volume 12, issue 1part1. There are many similarities between bacteriophages and animal cell viruses. The model incorporates a general theory for quantitatively interpreting cooperative sitespecific equilibrium binding data. Bacteriophage lambda l transcriptional switches can regulate cellular decisions lysis or lysogeny lysis. A the grf is the dependence of the production rate of a target promoter y axis on the concentration of one or more transcription factors x axis.
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