What is the Holliday model?
A conceptualization of general genetic recombination of newly replicated DNA during meiosis. An endonuclease nicks one strand of each of the two daughter duplexes at homologous sites which permits them to cross-over before being ligated.
What is the purpose of a Holliday junction?
The Holliday junction is a key intermediate in homologous recombination, a biological process that increases genetic diversity by shifting genes between two chromosomes, as well as site-specific recombination events involving integrases. They are additionally involved in repair of double-strand breaks.
What is Holliday junction resolution?
Holliday junction (HJ) resolution is essential for chromosome segregation at meiosis and the repair of stalled/collapsed replication forks in mitotic cells. All organisms possess nucleases that promote HJ resolution by the introduction of symmetrically related nicks in two strands at, or close to, the junction point.
What is branch migration in Holliday model?
Branch migration is the process by which base pairs on homologous DNA strands are consecutively exchanged at a Holliday junction, moving the branch point up or down the DNA sequence.
What is a Holliday structure What do they explain?
Holliday junction, cross-shaped structure that forms during the process of genetic recombination, when two double-stranded DNA molecules become separated into four strands in order to exchange segments of genetic information.
What is crossing over explain the Holliday model of mechanism of crossing over?
The frequency of crossing over between two genes on the same chromosome depends on the physical distance between these genes, with long distances giving the highest frequencies of exchange. Many of the popular models of crossing over were derived from a model proposed by Robin Holliday in 1964.
How does Holliday model of recombination repair DNA breaks?
Formation of the Holliday junction This junction can move along the DNA by the repeated melting and formation of base pairs. Each time the junction moves, base pairs are broken in the parental DNA molecules while identical base pairs are formed in the recombination intermediate. This process is called branch migration.
How is Holliday junction resolved specifically in bacteria?
RuvC is a specific endonuclease that resolves Holliday junctions in Bacteria.
How do Holliday junctions form?
Which type of DNA is connected by Holliday junction?
Which type of DNA is connected by a holiday junction? Explanation: Finishing of recombination usually requires resolution of the holiday junction by cutting the DNA strand. Two homologous DNA duplex is connected by a single holiday junction.
How are Holliday structures formed?
Which enzyme is important in the resolution of a Holliday junction?
But the functional junction-resolving enzyme is the SLX1-SLX4-MUS81-EME1 complex.