| Primary Identifier | IPR005736 | Type | Family |
| Short Name | Reverse_gyrase |
| description | This entry represents reverse gyrases found in both bacteria and archaea. Reverse gyrase, a fusion of a type I topoisomerase domain and a helicase domain, introduces positive supercoiling to increase the melting temperature of DNA double strands. Generally, these gyrases are encoded as a single polypeptide. An exception was found in Methanopyrus kandleri, where enzyme is split within the topoisomerase domain, yielding a heterodimer of gene products designated RgyB and RgyA. DNA topoisomerases are divided into two classes: type I enzymes (; topoisomerases I, III and V) break single-strand DNA, and type II enzymes (; topoisomerases II, IV and VI) break double-strand DNA []. Type I topoisomerases can be subdivided according to their structure and reaction mechanisms: type IA (bacterial and archaeal topoisomerase I, topoisomerase III and reverse gyrase) and type IB (eukaryotic topoisomerase I and topoisomerase V). Most of the Type I topoisomerases are ATP-independent and are responsible for relaxing positively and/or negatively supercoiled DNA. Reverse gyrase is a unique type IA topoisomerase in that it requires ATP and can introduce positive supercoils into DNA. |