Can transposons be replicative?

Replicative transposition is a particular transposition event that is used by transposable bacterial viruses to replicate their genome. The key enzyme responsible for replicative transposition is a DDE-recombinase (MuA) . The best studied transposable bacterial virus is bacteriophage Mu.

What is the function of Resolvase?

Function. Resolvase or recombinase (Rec) is a nuclease which is involved in DNA recombination. According to the binding residue, the recombinases are grouped to Tyr- and Ser-recombinase. Holliday junction resolvase (HJR) resolves 4-way DNA intermediates known as Holliday junctions.

What is replicative recombination?

The third type is replicative recombination, which generates a new copy of a segment of DNA. Many transposable elements use a process of replicative recombination to generate a new copy of the transposable element at a new location.

What is the difference between non replicative and replicative transposons?

What is replicative transposition? When a transposon replicates, makes a new copy and leaves the old copy behind, is considered as the replicative transposons while, when transposons move from one to another place by leaving a gap behind is considered as the non-replicative transposons.

What happens in replicative transposition?

Replicative transposition is a mechanism of transposition in molecular biology, proposed by James A. Shapiro in 1979, in which the transposable element is duplicated during the reaction, so that the transposing entity is a copy of the original element.

Which of the following is called Resolvase?

Which of the following is called a resolvase? Explanation: Nucleases that specifically cleave Holliday intermediates are often called resolvases, the Ruv-C protein is one of at least two such nucleases in E. coli. 8.

Which of the following is called a Resolvase?

d) Rec-A. Explanation: Nucleases that specifically cleave Holliday intermediates are often called resolvases, the Ruv-C protein is one of at least two such nucleases in E. coli.

What are the 3 methods of genetic recombination?

There are three methods of genetic recombination that are utilized by bacteria. They are transformation, transduction, and conjugation. Transformation uses genetic material from the environment, transduction uses a bacteriophage, and conjugation occurs between two different bacteria.

How do you separate two transposons after a replicative transposition?

Single-stranded cuts are made flanking the transposon in the donor molecule and a staggered cut is made in the target site on the recipient molecule. The ends are joined as shown, which causes the transposon to separate, resulting in two single-stranded copies of the transposon.

Which mechanism is used to repair a thymidine dimer in DNA?

photoreactivation
UV-induced thymine dimers can be repaired by photoreactivation, in which energy from visible light is used to split the bonds forming the cyclobutane ring. Another form of direct repair deals with damage resulting from the reaction between alkylating agents and DNA.

What is the difference between resolvase and replicative transposition?

Replicative transposition describes the movement of a transposon by a mechanism in which first it is replicated, and then one copy is transferred to a new site. Resolvase is enzyme activity involved in site-specific recombination between two transposons present as direct repeats in a cointegrate structure.

What are complex (replicative) transposons?

Complex (replicative) transposons have a gene for resolvase and an internal resolution site, in addition to the gene for transposase and two flanking inverted repeats. Replicative transposition proceeds as follows.

Does resolvase play a role in Tn3 replication?

Initially discovered as a repressor of transposase, resolvase also plays a role in facilitating Tn3 replication (Sherratt 1989). The transposon is flanked by a pair of 38bp inverted repeats. Replicative integration.

What is resolvase?

Resolvase is the product of the transposon’s tnpR gene. It is a small polypeptide – only 183 residues in the case of the transposon γδ.