What is the genome of lambda phage?
The genome contains 48,490 base pairs of double-stranded, linear DNA, with 12-base single-strand segments at both 5′ ends. In its circular form, the phage genome, therefore, is 48,502 base pairs in length. The lambda genome can be inserted into the E. coli chromosome and is then called a prophage.
How many genes are in lambda genome?
The lambda genome encodes 29 essential genes that participate in the lytic phase including the N, Q, and cro genes; regulatory genes like cI, cII, cIII, and int/xis that control lysogeny, and at least 38 nonessential or accessory genes (Fig. 9.3).
What is lambda DNA?
Lambda DNA, a linear, double-stranded phage DNA containing 12 bp single-stranded complementary 5′-ends, is derived from an Escherichia coli bacteriophage (Bacteriophage lambda cI857 Sam7). Lambda DNA can also be used as a substrate in restriction enzyme activity assays. …
Who determined 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 the life cycle of lambda phage?
Two types of life cycle of lambda (λ) phages exist, lytic and lysogenic cycle. In the lytic case the phage attached to the host cell and injects its nucleic acid. Afterwards transcription, translation and replication occur followed by phage assembly.
Why is it called lambda phage?
…a temperate bacteriophage is called lambda (λ) virus, which readily causes lysogeny in certain species of the bacterium Escherichia coli. The DNA of the λ bacteriophage is integrated into the DNA of the E. coli host chromosome at specific regions called attachment sites.
What are the advantages of lambda phage vector?
The efficiency of packaging and infection, and the simplicity of plaque screening are advantages of lambda as a cloning vector. A number of ingenious modifications help overcome the disadvantages associated with its mode of growth and its size.
Do bacteriophages have DNA?
Bacteriophages are composed of proteins that encapsulate a DNA or RNA genome, and may have structures that are either simple or elaborate. Their genomes may encode as few as four genes (e.g. MS2) and as many as hundreds of genes. Bacteriophages are ubiquitous viruses, found wherever bacteria exist.
What is the size of lambda phage?
Bacteriophage Lambda Infection and DNA Replication A λ virion consists of a 48.5 kb dsDNA genome tightly packaged within an icosahedral protein shell and a tail, which serves to deliver the linear genome through the cell envelope into the cytoplasm of an Escherichia coli cell.
How is lambda phage used?
Enterobacteria phage λ (lambda phage, coliphage λ) is a bacterial virus, or bacteriophage, that infects the bacterial species Escherichia coli. coli, causing DNA in the head of the phage to be ejected through the tail into the cytoplasm of the bacterial cell.
What is lambda phage vector?
Enterobacteria phage λ (lambda phage, coliphage λ) is a bacterial virus, or bacteriophage, that infects the bacterial species Escherichia coli. Lambda phage consists of a virus particle including a head (also known as a capsid), tail and tail fibers. The head contains the phage’s double-stranded circular DNA genome.
When does lambda phage integrate into the host chromosome?
Lambda phage. However, under certain conditions, the phage DNA may integrate itself into the host cell chromosome in the lysogenic pathway. In this state, the λ DNA is called a prophage and stays resident within the host’s genome without apparent harm to the host. The host is termed a lysogen when a prophage is present.
How is the linear phage genome injected into the host?
The linear phage genome is injected through the outer membrane. The DNA passes through the mannose permease complex in the inner membrane (encoded by the manXYZ genes) and immediately circularises using the cos sites, 12-base G-C-rich cohesive “sticky ends”. The single-strand viral DNA ends are ligated by host DNA ligase.
How many base pairs are in lambda DNA?
Duplex DNA is isolated from bacteriophage lambda (cI857 ind 1 Sam 7). Lambda DNA is 48,502 base pairs in length Need a custom/large volume order?
What is the role of rightward transcription in lambda phage?
Rightward transcription expresses the O, P and Q genes. O and P are responsible for initiating replication, and Q is another antiterminator that allows the expression of head, tail, and lysis genes from PR’ . For the first few replication cycles, the lambda genome undergoes θ replication (circle-to-circle).