What is cos site of phage lambda?
cos. The cos site is a ≈200 bp long segment that is required to both initiate and terminate the packaging of a monomeric genome from concatemeric DNA. The site where terminase introduces staggered nicks to generate the cohesive ends is called cosN (fig. 2).
Which of the following is site-specific recombination?
Which of the following is an example of site specific recombination? Explanation: The phage particles attach to the bacterial genome using site-specific recombination reaction. This is via the means of att sites.
What is the use of Cos site?
Cohe sive end sites, nucleotide sequences that are recognized for packaging a phage DNA molecule into its protein capsule.
What is cos site?
A 12-nucleotide bases-long segment of single stranded DNA that exists at both ends of the bacteriophage lambda’s double-stranded genome. …
What is attL and attR?
The attL and attR sites are substrates for the excision reaction, and each is composed of one B-type half-site and one P-type half-site.
What is attP phage?
Notes. In the free phage, the att site is referred to as attP (phage attachment site) while the corresponding site in a host genome is called attB (bacterial attachment site). After integration occurs to create a prophage, these sites are then known as attL (left end of prophage) and attR (right end of prophage).
Is there site-specific recombination in bacteriophage lambda?
Site-specific recombination in bacteriophage lambda☆. Abstract. Lambda attB-attP is a derivative of bacteriophage lambda that contains both attB and attP, two sites required for integrative recombination. Lambda attB-attP can undergo int-mediated recombination to yield progeny phages whose DNA is 15% shorter than that of the parental phage.
What is the lytic and lysogenic cycle of lytic Lambda?
Lambda consists of two types of life cycles, the lytic and lysogenic. The events of lytic cycle, starting with adsorption, at 37°C occurs as below: Time (t) = 0 minutes: Phage adsorbed and DNA is injected = 3 minutes: First early mRNA is synthesized
Can λ attB-attP undergo int-mediated recombination with lysogenic bacteria?
Lambda attB-attP can undergo int -mediated recombination to yield progeny phages whose DNA is 15% shorter than that of the parental phage. We have studied intracellular phage DNA from an infection of lysogenic bacteria with λ attB-attP in the presence of int gene product, rifampicin and chloramphenicol.
What is the life cycle of linear phage?
Life cycle of phage λ is 45 minutes long, as compared to 22-25 minutes long life cycle of T4 phage. In general the life cycle of most phages at 37°C varies between 22 and 60 minutes. After injection, the linear phage DNA is circularized. The cos site results in a circular form of DNA which starts the two events: