What is the role of topoisomerase 1?
Like the yeasts, all higher eukaryotes contain a single topoisomerase I enzyme that plays a major role in supporting fork movement during replication and in relaxing transcription-related supercoils. Topoisomerase I is indispensable during development and probably also during cell division (58, 59).
Do humans have topoisomerase 1?
Inhibition. As topoisomerases generate breaks in DNA, they are targets of small-molecule inhibitors that inhibit the enzyme. The human topoisomerase type IB enzyme forms a covalent 3-phosphotyrosine intermediate, the topoisomerase 1-cleavage-complex (Top1cc).
What is topoisomerase give an example?
A type I topoisomerase cuts one strand of a DNA double helix, relaxation occurs, and then the cut strand is re-ligated. Examples of type IA topoisomerases include prokaryotic topoisomerase I and III, eukaryotic topoisomerase IIIα and topoisomerase IIIβ and reverse gyrase.
How many types of topoisomerase are there?
Classes. DNA topoisomerases are divided into two classes: type I enzymes (EC; topoisomerases I, III and V) break single-strand DNA, and type II enzymes (EC; topoisomerases II, IV and VI) break double-strand DNA.
Where are topoisomerase found?
The mitochondrial DNA of animal cells is a circular, double-stranded DNA that requires the activity of topoisomerase to be replicated. The classes of topoisomerase found in the mitochondria are I, IIβ, IIIα.