Which is the site-specific recombination?
Site-specific recombination is an exchange that occurs between pairs of defined sequences (target sites) residing on the same DNA molecule or on two different DNA molecules. The result of the exchange may be integration, excision, or inversion of DNA sequences.
What is difference between site-specific and homologous recombination?
The key difference between homologous recombination and site-specific recombination is that in homologous recombination, genetic material is exchanged between two identical molecules of double-stranded or single-stranded nucleic acids such as DNA or RNA, whereas in site-specific recombination, DNA strand exchange takes …
What is the site on bacterial DNA required for integration of lambda phage DNA?
Bacterial DNA has an attachment sequence called attB. Bacterial DNA and λ-phage DNA align at the “O” region of the attachment sequences. During integration, int protein induces two double-stranded breaks that are resolved, resulting in the integration of the phage DNA into the bacterial DNA.
Which of the lambda phage genes are required for prophage excision?
The product of the phage gene int, which maps immediately to the right of att, is required for both integration and excision of the λ prophage (5). The excision reaction, in addition, requires the product of a second phage gene, xis, which maps immediately to the right of the int gene (6).
What is Transpositional site-specific recombination?
Transposition is the process by which genetic elements move between different locations of the genome, whereas site-specific recombination is a reaction in which DNA strands are broken and exchanged at precise positions of two target DNA loci to achieve determined biological function.
What is lambda integrase?
Bacteriophage lambda integrase (Int) is a versatile site-specific recombinase. In concert with other proteins, it mediates phage integration into and excision out of the bacterial chromosome. Int recombines intramolecular sites in inverse or direct orientation or sites on separate DNA molecules.
Which enzyme plays an role in site-specific recombination?
The insertion of a circular bacteriophage lambda DNA chromosome into the bacterial chromosome. In this example of site-specific recombination, the lambda integrase enzyme binds to a specific “attachment site” DNA sequence on each chromosome, (more…)
What is the specific site for recombination by Cre enzyme?
The Cre protein encoded by the coliphage P1 is a 38-kDa protein that efficiently promotes both intra- and intermolecular synapsis and recombination of DNA both in Escherichia coli and in vitro. Recombination occurs at a specific site, called lox, and does not require any other protein factors.
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).
What is the phage required for integration of Lambda DG into recipient DNA known as?
Prophage integration The integration of phage λ takes place at a special attachment site in the bacterial and phage genomes, called attλ.
Which protein recognize the cos site of lambda DNA?
The 12 nucleotide 5′ overhangs at the cos-ends of the linear Lambda DNA are the result of a cut by the enzyme terminase. This enzyme is encoded by Lambda itself and acts like a restriction enzyme during the replication of the phage DNA. It is an endonuclease specific for the cos-site in multimeric phage DNA.
What is Transpositional recombination?
Transpositional recombination is a process in which a mobile element is inserted into a target DNA. It may occur by one of two mechanisms: (1) directly as DNA, (2) through RNA. The mobile elements that transpose through DNA are called transposons and those via RNA are referred to as retrotransposons.