Table of Contents
What is the genetic material of lambda phage?
Enterobacteria phage λ (lambda phage) is a temperate bacteriophage that infects Escherichia coli. Lambda phage is a virus particle consisting of a head, containing 48,514 base-pairs of double-stranded linear DNA as its genetic material, and a tail that can have tail fibers.
Is lambda DNA circular or linear?
Our lambda DNA is linear. We do not sell Lambda DNA in a circular form. Theoretically, it could be ligated to form circles but, due to its large size, it is difficult to achieve.
How many genes does a lambda phage have?
Bacteriophage lambda is a model phage for most other dsDNA phages and has been studied for over 60 years. Although it is probably the best-characterized phage there are still about 20 poorly understood open reading frames in its 48-kb genome.
Who determine the sequence of lambda phage?
Explanation: The phage DNA molecule, unlike the bacterial plasmid DNA, exists usually in a linear conformation and DNA is a duplex molecule. 3. Who determined the sequence of Lambda phage? Explanation: The exact sequencing of lambda phage of 49 kb was done with Sanger sequencing method in 1982.
What is reason of genome Circularization in lambda phage?
Circularization of infecting DNA within the host cell is a rather common amongst bacterial viruses to protect the viral genome ends from nucleases, to convert the linear genome to an integrative precursor or to give rise to the replicative form of the genome.
What is lambda phage in biotechnology?
A lambda phage is a bacteriophage that infects E. Coli cells. This phage, like any virus, readily undergoes two types of life cycles – the lytic cycle and the lysogenic cycle. In the lytic cell, the phage hijacks the machinery of the cell to replicate the DNA and produce viral proteins.
Why is lambda phage called temperate phage?
Bacteriophage λ is a temperate phage, which, upon infection of Escherichia coli, enters either the lytic or lysogenic replication pathway. The latter is defined by the integration of the λ prophage within the bacterial host genome, where it is quiescently inherited by daughter cells.
Why is lambda DNA used?
Lambda DNA (48,502 bp) may be used as a molecular weight size marker during nucleic acid gel analysis following digestion with a restriction enzyme (such as HindIII). Lambda DNA can also be used as a substrate in restriction enzyme activity assays.
Why the phage DNA is circular?
The reason of circular DNA of phage before integrate into bacteria because they want to not have linear DNA form. If they circular DNA is secured from digestion of liner DNA.
Why is it called lambda phage?
Enterobacteria phage λ (lambda phage, coliphage λ, officially Escherichia virus Lambda) is a bacterial virus, or bacteriophage, that infects the bacterial species Escherichia coli (E. coli). It was discovered by Esther Lederberg in 1950….Lambda phage.
| Escherichia virus Lambda | |
|---|---|
| Genus: | Lambdavirus |
| Species: | Escherichia virus Lambda |
How the lambda phage genome integrates into its host?
During infection, the phage particle recognizes and binds to its host, E. coli, causing DNA in the head of the phage to be ejected through the tail into the cytoplasm of the bacterial cell. However, under certain conditions, the phage DNA may integrate itself into the host cell chromosome in the lysogenic pathway.
What does lambda phage do?
Lambda phage is a non-contractile tailed phage, meaning during an infection event it cannot ‘force’ its DNA through a bacterial cell membrane. It must instead use an existing pathway to invade the host cell, having evolved the tip of its tail to interact with a specific pore to allow entry of its DNA to the hosts.
How many base pairs are in a lambda phage genome?
Linear layout of lambda phage genome with major operons, promoter regions and capsid coding genes. The genome contains 48,490 base pairs of double-stranded, linear DNA, with 12-base single-strand segments at both 5′ ends.
What is the difference between lambda and prophage?
The lambda genome can be inserted into the E. coli chromosome and is then called a prophage. See section below for details. Lambda phage is a non-contractile tailed phage, meaning during an infection event it cannot ‘force’ its DNA through a bacterial cell membrane.
What is lambda phage integration and excision?
A newer cloning system uses the lambda phage integration and excision sites for cloning genes from one vector to another (Fig. 3.27 ). Lambda phage exists as a phage but also integrates into the E. coli chromosome at the attB site to form a prophage.
What is the life cycle of phage lambda?
Life Cycles of Phage Lambda: Upon adsorption on the lamb receptor of the host cell, lambda gDNA is injected through the tail which forms a hollow tube through which the DNA passes to the cell. The phage λ leads two life cycles, the lytic cycle and the lysogenic cycle after injecting its DNA into E.coli cell.