What is a attB site?
The attB site is a short DNA sequence (less than 30 bp) corresponding to the crossover region at which strand exchange takes place (7). Two imperfect inverted repeats that bind to the integrase surround a 7-bp overlap region delimited by the scattered cuts made by the recombinase.
What do you mean by 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.
Are transposons site specific?
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.
Which of the following is an example of site-specific recombination?
8. 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. Explanation: Excision of the genome of lamda phage from the bacterial genome requires IHF and XIS that is coded by the bacteriophage.
What is LR reaction?
The LR Reaction, again is a recombination reaction between attL and attR sites. The reaction generates an expression clone and is catalyzed by recombinant proteins. Recombination between these sites generates two molecules. One molecule contains the DNA segment of interest, the other molecule is a by-product.
What is the advantage of Gateway cloning?
One of the main advantages of the GATEWAY Cloning Technology is that once you have made an Entry Clone the gene of interest can be easily subcloned into a wide variety of Destination Vectors using the LR Reaction (see Figure 3).
Why is site recombination conservative?
The process is considered “conservative” because there is no net gain or loss of sequence information during the recombination process (i.e., no target-site duplication as in DDE-type transposition). This mechanism also does not require any high-energy cofactors, such as ATP (Grindley et al. 2006).
Why are transposons so useful as genetic research tools?
Given their relatively simple design and inherent ability to move DNA sequences, transposons are highly compatible at transducing genetic material, making them ideal genetic tools.
What is recombination example?
Recombination occurs when two molecules of DNA exchange pieces of their genetic material with each other. One of the most notable examples of recombination takes place during meiosis (specifically, during prophase I), when homologous chromosomes line up in pairs and swap segments of DNA.
What is recombination Slideshare?
Recombination is a process by which pieces of DNA are broken and recombined to produce new combinations of alleles. During meiosis in eukaryotes, genetic recombination involves the pairing of homologous chromosomes. This may be followed by information exchange between the chromosomes.
What is BP and LR reaction?
The BP reaction creates an attL-flanked entry clone. The LR reaction creates an expression clone with all of the components necessary for gene expression. The LR Reaction takes place between the attL sites of the generated entry clone and the attR sites of the destination vector.
Where are the attB sites located in the BLA?
We placed attB sites from each system immediately downstream of the bla signal peptide coding sequence, which directs transport of β-lactamase to the periplasm and is removed in the mature protein. β-lactamase is generally tolerant of insertions into this region.
Where are the attL and ATTR sites located?
When each system is present as attL and attR sites, they are associated with fragment sequences bla’ (the 5′ region upstream of the cleavage site including the promoter and signal sequence) and ‘bla (the 3′ region comprising the mature protein sequence), respectively (Fig. 1a).
What is the function of the attB HK site?
The attB HK site comprises a 7 bp core, or overlap, (O) region where strand exchange occurs, and flanking B and B′ arm regions of 7 bp each that are recognized by Int monomers to form a synaptic complex, although sites shorter than this 21 bp have been shown to be functional but with low efficiency [ 27 ].
What are the minimal sizes of attP and attB?
This assay system was also used to define the minimal sizes of attB and attP at 34 bp and 39 bp, respectively. Furthermore, precise and efficient intermolecular integration of an incoming plasmid bearing attP into an established Epstein-Barr virus plasmid bearing attB was documented in human cells.