Protein Domain : IPR000380

Type:  Family Name:  DNA topoisomerase, type IA
Description:  This entry describes the type IA topoisomerases, which are highly conserved enzymes that are structurally distinct from type IB enzymes. The structures of both topoisomerases I and III have been elucidated, and consist of four domains that together form a toroidal molecule with a central hole that is large enough to accommodate single- and double-stranded DNA []. It is believed that the domains transiently separate from one another to allow the entrance and exit of DNA strands.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. Short Name:  Topo_IA

3 Child Features

DB identifier Type Name
IPR005738 Family DNA topoisomerase III
IPR028612 Family DNA topoisomerase I, type IA
IPR005736 Family Reverse gyrase

7 Contains

DB identifier Type Name
IPR013826 Domain DNA topoisomerase, type IA, central region, subdomain 3
IPR006171 Domain Toprim domain
IPR013824 Domain DNA topoisomerase, type IA, central region, subdomain 1
IPR013497 Domain DNA topoisomerase, type IA, central
IPR013825 Domain DNA topoisomerase, type IA, central region, subdomain 2
IPR003602 Domain DNA topoisomerase, type IA, DNA-binding domain
IPR003601 Domain DNA topoisomerase, type IA, domain 2

2 Cross Referencess

Identifier
PTHR11390
PR00417

0 Found In

3 GO Annotations

GO Term Gene Name
GO:0003677 IPR000380
GO:0003917 IPR000380
GO:0006265 IPR000380

3 Ontology Annotations

GO Term Gene Name
GO:0003677 IPR000380
GO:0003917 IPR000380
GO:0006265 IPR000380

0 Parent Features

3256 Proteins

DB identifier UniProt Accession Secondary Identifier Organism Name Length
94303 D8RIM2 PAC:15423298 Selaginella moellendorffii 794  
417843 D8S3U1 PAC:15406817 Selaginella moellendorffii 408  
168492 D8R567 PAC:15422213 Selaginella moellendorffii 871  
123748 D8SSL3 PAC:15403346 Selaginella moellendorffii 795  
410336 D8REF7 PAC:15404795 Selaginella moellendorffii 216  
evm.model.supercontig_157.4 PAC:16409827 Carica papaya 867  
evm.model.supercontig_246.4 PAC:16414635 Carica papaya 268  
evm.model.supercontig_246.5 PAC:16414636 Carica papaya 619  
evm.model.supercontig_37.4 PAC:16418711 Carica papaya 460  
29724.m000868 B9S3M8 PAC:16806595 Ricinus communis 311  
30149.m000235 B9SN22 PAC:16820644 Ricinus communis 833  
30183.m001296 B9RRL8 PAC:16822981 Ricinus communis 865  
28226.m000877 B9SPT5 PAC:16800410 Ricinus communis 1071  
Cucsa.337050.1 PAC:16978549 Cucumis sativus 603  
Cucsa.179950.1 A0A0A0KVB6 PAC:16967253 Cucumis sativus 327  
Cucsa.179950.2 PAC:16967254 Cucumis sativus 226  
Cucsa.251840.1 A0A0A0L9C7 PAC:16971857 Cucumis sativus 867  
Cucsa.311150.1 PAC:16976641 Cucumis sativus 411  
Cucsa.311140.2 PAC:16976640 Cucumis sativus 1135  
Cucsa.311140.1 PAC:16976639 Cucumis sativus 1173  
orange1.1g001100m PAC:18109309 Citrus sinensis 1158  
orange1.1g001106m PAC:18109310 Citrus sinensis 1157  
orange1.1g039214m A0A067EUC1 PAC:18126639 Citrus sinensis 146  
orange1.1g046997m PAC:18126654 Citrus sinensis 807  
orange1.1g045217m PAC:18138437 Citrus sinensis 224  
orange1.1g048704m PAC:18138420 Citrus sinensis 220  
orange1.1g021205m A0A067E4X6 PAC:18129251 Citrus sinensis 316  
AT4G31210.1 F4JRX3 PAC:19645326 Arabidopsis thaliana 1284  
AT5G63920.1 Q9LVP1 PAC:19666283 Arabidopsis thaliana 926  
AT3G42860.1 Q9M1L9 PAC:19659073 Arabidopsis thaliana 372  

5 Publications

First Author Title Year Journal Volume Pages PubMed ID
            7770916
            11395412
            12596227
            12042765
            11239459