4 edition of Mutational analysis of bacteriophage lambda terminase found in the catalog.
Mutational analysis of bacteriophage lambda terminase
Randall C. Willis
Thesis (M.Sc.)--University of Toronto, 1992.
|Series||Canadian theses = Thèses canadiennes|
|The Physical Object|
|Pagination||2 microfiches : negative.|
Synthesis of proteins and nucleic acid[ edit ] Within minutes, bacterial ribosomes start translating viral mRNA into protein. The structure of secondary attachment sites is discussed in terms of current models for lambda site-specific recombination. Gene ; — J Bacteriol b; 8 —9. The Self-Association Domain s It is presumed that rotationally symmetric gpA subunits bound to cosN are responsible for duplex nicking based, in part, on the two-fold rotational symmetry of the cosN sequence see fig.
Two important developments suggested that lambda may be suitable as a cloning vector. Virus assembly requires that monomeric virion DNA molecules be produced from concatemers during packaging of the DNA into a procapsid. Each of these catalytic activities is discussed in turn below. Lysis, by tailed phages, is achieved by an enzyme called endolysinwhich attacks and breaks down the cell wall peptidoglycan.
Like T4, however, it still injects its DNA into the host cell, although the tail is non-contractile. This presents problems when you are trying to create a genomic library of a large genome such as with plants. Control of phage genome excision in induction[ edit ] The phage genome is still inserted in the host genome and needs excision for DNA replication to occur. Google Scholar 3. The prophage is duplicated with every subsequent cell division of the host.
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There exists a remarkable genetic mechanism or switch that determines which cycle is followed and this was the first developmental switch to be described at the molecular level. We note that terminase remains bound to the concatemer after the DNA-filled capsid has been released see fig.
The new intact transcript has one copy of both xis and int, so approximately equal concentrations of xis and int proteins are produced. When RNA polymerase transcribes these regions, it recruits N and forms a complex with several host Nus proteins.
The C-terminal 40 amino acids of the protein are required for efficient gpA-binding interactions and holoenzyme formation.
Lytic phages are more suitable for phage therapy. This intermediate has a molecular weight consistent with a direct fusion of gpC and gpE; presumably, proteolysis of pY yields both pX1 31 kDa and pX2 29 kDa.
About progeny phages are liberated the burst size is about Many of these effects are probably indirect, hence the challenge becomes to identify the direct interactions among bacteria and phage.
Host DNA gyrase puts negative supercoils in the circular chromosome, causing A-T-rich regions to unwind and drive transcription. Adsorption The life-cycle of lambda phage begins when it absorbs to the surface of the host bacterial cell.
This I1 site introduces an intrinsic bend into the duplex, and is also specifically recognized by IHF. Google Scholar For that reason, N is called an anti termination protein. Bacteriophage lambda Integration If the phage decides to undergo lysogeny, then its DNA inserts at a specific site on the host chromosome called attB which is inbetween two genes and so viral DNA insertion does not disrupt the functioning of the host.
The proteins encoded by cro binds to PL and PR and reduce the expression of cl, N, red and xis genes. A defined system for in vitro lambda DNA packaging.
No Q results in no extension of the PR' promoter's reading frame, so no lytic or structural proteins are made. The whole particle consists of 12—14 different proteins with more than protein molecules total and one DNA molecule located in the phage head. Once inside the cell the single stranded molecule acts as the template for the synthesis of a complementary strand, resulting in normal double stranded DNA.
After treatment of lysogenic bacteria with UV light. Examples are the conversion of harmless strains of Corynebacterium diphtheriae or Vibrio cholerae by bacteriophages, to highly virulent ones that cause diphtheria or cholerarespectively.
It consists of 48, base pairs of known sequence. Lysogeny is maintained solely by cI. Structural proteins and phage genomes self-assemble into new phage particles. Binding of gpA to the cosNR half-site more Virus assembly requires that monomeric virion DNA molecules be produced from concatemers during packaging of the DNA into a procapsid.
Lysis is brought about by three viral proteins: R and S. However, some DNA phage such as T4 may have large genomes with hundreds of genes; the size and shape of the capsid varies along with the size of the genome.At this point they initiate the reproductive cycle, resulting in lysis of the host cell.
As the lysogenic cycle allows the host cell to continue to survive and reproduce, the virus is replicated in all offspring of the cell. An example of a bacteriophage known to follow the lysogenic cycle and the lytic cycle is the phage lambda of E.
coli. The lysis-lysogeny decision of bacteriophage lambda (λ) is a paradigm for developmental genetic networks. There are three key features, which characterize the network.
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.
Second, the lysogenic prophage Cited by: Bacteriophage lambda Other names i ›Coliphage lambda ›Enterobacteria phage lambda ›Escherichia virus Lambda ›Lambda phage ›bacteriaphage lambda More». The Ogr protein is a residue, zinc-binding transcription factor essential for activation of late gene expression in bacteriophage P2.
Analysis of C-terminal truncated proteins generated by stop. Allet B, Bukhari AI. Analysis of bacteriophage mu and lambda-mu hybrid DNAs by specific endonucleases. J Mol Biol. Mar 15; 92 (4)– [Allet B, Jeppesen PG, Katagiri KJ, Delius H. Mapping the DNA fragments produced by cleavage by lambda DNA with endonuclease RI.
B M B Part Four - III = Chpt. Transcriptional regulation in bacteriophage lambda Figure Zygotic induction λ E. coli K12 (lambda) "wild type" λ λ X X mutant 1 mutant 2 mutant 3 Mate with Hfr, nonmutant K12 (lambda) Not lyse Lyse (zygotic induction) Not lyse UV E.
Lederberg called the phage released by induction of E. coli K