InterPro : IPR000565

Name  DNA topoisomerase, type IIA, subunit B Short Name  Topo_IIA_B
Type  Family 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 II topoisomerases are ATP-dependent enzymes, and can be subdivided according to their structure and reaction mechanisms: type IIA (topoisomerase II or gyrase, and topoisomerase IV) and type IIB (topoisomerase VI). These enzymes are responsible for relaxing supercoiled DNA as well as for introducing both negative and positive supercoils [].Type IIA topoisomerases together manage chromosome integrity and topology in cells. Topoisomerase II (called gyrase in bacteria) primarily introduces negative supercoils into DNA. In bacteria, topoisomerase II consists of two polypeptide subunits, gyrA and gyrB, which form a heterotetramer: (BA)2. In most eukaryotes, topoisomerase II consists of a single polypeptide, where the N- and C-terminal regions correspond to gyrB and gyrA, respectively; this topoisomerase II forms a homodimer that is equivalent to the bacterial heterotetramer. There are four functional domains in topoisomerase II: domain 1 (N-terminal of gyrB) is an ATPase, domain 2 (C-terminal of gyrB) is responsible for subunit interactions (differs between eukaryotic and bacterial enzymes), domain 3 (N-terminal of gyrA) is responsible for the breaking-rejoining function through its capacity to form protein-DNA bridges, and domain 4 (C-terminal of gyrA) is able to non-specifically bind DNA [].Topoisomerase IV primarily decatenates DNA and relaxes positive supercoils, which is important in bacteria, where the circular chromosome becomes catenated, or linked, during replication []. Topoisomerase IV consists of two polypeptide subunits, parE and parC, where parC is homologous to gyrA and parE is homologous to gyrB.This entry represents subunit B found in topoisomerase II (gyrB) and topoisomerase IV (parE), primarily of bacterial origin, and which functions in ATP hydrolysis and subunit interaction. It does not include the topoisomerase II enzymes composed of a single polypeptide, as are found in most eukaryotes.
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Sequence Features

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Proteins

InterPro protein domain ID --> Contigs

 

Other

2 Child Features

Id Name Short Name Type
IPR005740 DNA topoisomerase 4 subunit B, Gram-positive ParE Family
IPR011557 DNA gyrase, subunit B GyrB Family

7 Contains

Id Name Short Name Type
IPR006171 Toprim domain Toprim_domain Domain
IPR020568 Ribosomal protein S5 domain 2-type fold Ribosomal_S5_D2-typ_fold Domain
IPR013506 DNA topoisomerase, type IIA, subunit B, domain 2 Topo_IIA_bsu_dom2 Domain
IPR013760 DNA topoisomerase, type IIA-like domain Topo_IIA_like_dom Domain
IPR013759 DNA topoisomerase, type IIA, central domain Topo_IIA_cen_dom Domain
IPR018522 DNA topoisomerase, type IIA, conserved site TopoIIA_CS Conserved_site
IPR002288 DNA gyrase B subunit, C-terminal DNA_gyrase_B_C Domain

0 Found In

1 Parent Features

Id Name Short Name Type
IPR001241 DNA topoisomerase, type IIA Topo_IIA Family

7 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
Watt PM Structure and function of type II DNA topoisomerases. 1994 Biochem J 303 ( Pt 3) 681-95
Corbett KD The structural basis for substrate specificity in DNA topoisomerase IV. 2005 J Mol Biol 351 545-61
Huang WM Bacterial diversity based on type II DNA topoisomerase genes. 1996 Annu Rev Genet 30 79-107



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)