How topoisomerases unknot knots that are formed in DNA

How to solve the junction formed of DNA by topoisomerase: Introduction: The study of the properties of geometric objects under deformation is called topology, and the topology subdomain discussed in this paper is called junction theory (Adams 6). There are two main differences in mathematics. One is infinitely thin, the other two are always closed. DNA is very similar to the size and shape of mathematical knots. Naturally, knots often tie DNA.

DNA gyrase is an essential tetrameric enzyme involved in DNA synthesis and is understood to be the only type II topoisomerase present in Mtb. The structure of DNA gyrase consists of two subunits called GyrA and GyrB, which first form homodimers called A2 and B2 and then form larger heterodimers called A2B2. These two subunits serve different functions from the GyrA subunit for cleavage of the positive supercoiled DNA while the GyrB subunit promotes ATP hydrolysis. The GyrA and GyrB subunits are the products of the gyrA and gyrB genes. The gyrB gene has 34 base pairs upstream of the gyrA gene, both of which are located near the origin of replication (Unniraman, Chatterji and Nagaraja, 2002).

Type II topoisomerase acts by causing transient double-stranded DNA cleavage and even even double-stranded DNA passage. As a result, these enzymes eliminate supercoil distortion in DNA and can solve knotted or intertwined double-stranded molecules. Type II topoisomerases are required for recombination, chromosome segregation, and appropriate chromosome concentration and deconcentration (Nitiss, 1998). Although lower eukaryotes only encode a single type II topoisomerase, vertebrates use two separate types of enzymes, topoisomerase II-α and II-β (Velez-Cruz and Osheroff, 2004). These enzymes display high amino acid sequence identity (~ 70%) and similar enzymatic features. These protoplasts have different molecular weights (170 vs. 180 kDa, corresponding) and are encoded by different genes (Austin and Marsh, 1998).

DNA topoisomerase is an important ribozyme that regulates DNA topology during various DNA exchanges (eg, replication, transcription, and recombination) by catalytic chain transfer reaction by cleavage / recombination of DNA double helix (Wang, 1996 ). Topoisomerases fall into two categories based on their fundamental differences in enzyme catalysis: type I and type II topoisomerases. Type I topoisomerase catalyzes cleavage / religation by temporarily enzymatically linked single stranded DNA cleavage. Type II topoisomerase catalyzes cleavage / recombination by enzyme-linked double strand breaks