| Type: | Domain | Name: | DNA topoisomerase V, catalytic domain |
| Description: | DNA topoisomerases regulate the number of topological links between two DNA strands (i.e. change the number of superhelical turns) by catalysing transient single- or double-strand breaks, crossing the strands through one another, then resealing the breaks []. These enzymes have several functions: to remove DNA supercoils during transcription and DNA replication; for strand breakage during recombination; for chromosome condensation; and to disentangle intertwined DNA during mitosis [, ]. 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 [].Topoisomerases are involved in controlling and maintaining the topology of DNA and are present in all kingdoms of life. Unlike all other types of topoisomerases, similar type IB enzymes have only been identified in bacteria and eukarya. The only putative type IB topoisomerase in archaea is represented by Methanopyrus kandleri topoisomerase V. Uniquely, this topoisomerase also displays DNA repair activities []. Despite several common functional characteristics, topoisomerase V shows no sequence similarity to other members of the same type. The topoisomerase V protein consists of an N-terminal catalytic domain followed by 24 tandem helix-hairpin-helix (HhH) motifs. The N-terminal domain can relax DNA in the absence of any HhH motifs, while the HhH motifs are required for stable protein-DNA complex formation [, ].This entry represents the catalytic domain of topoisomerase V. | Short Name: | TopoV_catalytic_domain |
