InterPro : IPR013497

Name  DNA topoisomerase, type IA, central Short Name  Topo_IA_cen
Type  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 [].Type I topoisomerases are ATP-independent enzymes (except for reverse gyrase), and 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). These enzymes are primarily responsible for relaxing positively and/or negatively supercoiled DNA, except for reverse gyrase, which can introduce positive supercoils into DNA. Type IA topoisomerases are comprised of four domains that together form a toroidal structure with a central hole large enough to accommodate single- and double-stranded DNA: an N-terminal alpha/beta Toprim domain, domain 2 and the C-terminal domain 4 are winged-helix domains, and domain 3 is a beta-barrel. Domains 1 (Toprim) and 3 form the active site of the enzyme, while the winged helix domains 2 and 4 form a single-strand DNA-binding groove [, ]. This entry represents the central portion of the enzyme, which covers domains 2 and 3 in topoisomerase type IA enzymes.

Sequence Features

GO Displayer


InterPro protein domain ID --> Contigs



0 Child Features

5 Contains

Id Name Short Name Type
IPR013826 DNA topoisomerase, type IA, central region, subdomain 3 Topo_IA_cen_sub3 Domain
IPR003602 DNA topoisomerase, type IA, DNA-binding domain Topo_IA_DNA-bd_dom Domain
IPR003601 DNA topoisomerase, type IA, domain 2 Topo_IA_2 Domain
IPR013824 DNA topoisomerase, type IA, central region, subdomain 1 Topo_IA_cen_sub1 Domain
IPR013825 DNA topoisomerase, type IA, central region, subdomain 2 Topo_IA_cen_sub2 Domain

5 Found In

Id Name Short Name Type
IPR000380 DNA topoisomerase, type IA Topo_IA Family
IPR005733 DNA topoisomerase I, bacterial-type TopoI_bac-type Family
IPR005739 DNA topoisomerase I, archeal-type TopoI_arch Family
IPR005736 Reverse gyrase Reverse_gyrase Family
IPR005738 DNA topoisomerase III TopoIII Family

0 Parent Features

6 Publications

First Author Title Year Journal Volume Pages
Roca J The mechanisms of DNA topoisomerases. 1995 Trends Biochem Sci 20 156-60
Champoux JJ DNA topoisomerases: structure, function, and mechanism. 2001 Annu Rev Biochem 70 369-413
Gadelle D Phylogenomics of type II DNA topoisomerases. 2003 Bioessays 25 232-42
Wang JC Cellular roles of DNA topoisomerases: a molecular perspective. 2002 Nat Rev Mol Cell Biol 3 430-40
Perry K Structure of a complex between E. coli DNA topoisomerase I and single-stranded DNA. 2003 Structure 11 1349-58
Mondragón A The structure of Escherichia coli DNA topoisomerase III. 1999 Structure 7 1373-83

To cite PlanMine, please refer to the following publication:

Rozanski, A., Moon, H., Brandl, H., Martín-Durán, J. M., Grohme, M., Hüttner, K., Bartscherer, K., Henry, I., & Rink, J. C.
PlanMine 3.0—improvements to a mineable resource of flatworm biology and biodiversity
Nucleic Acids Research, gky1070. doi:10.1093/nar/gky1070 (2018)