Function and Biology

CRYSTAL STRUCTURE OF E. COLI DNA TOPOISOMERASE III

Source organism: Escherichia coli
Biochemical function: metal ion binding
Biological process: DNA topological change
Cellular component: not assigned

EC 5.99.1.2: DNA topoisomerase

Reaction catalysed:
ATP-independent breakage of single-stranded DNA, followed by passage and rejoining.
Comments:
  • Brings about the conversion of one topological isomer of DNA into another, e.g. the relaxation of superhelical turns in DNA, the interconversion of simple and knotted rings of single-stranded DNA, and the intertwisting of single-stranded rings of complementary sequences (cf. EC 5.99.1.3).
Systematic name:
DNA topoisomerase
Alternative Name(s):
  • Omega-protein
  • Deoxyribonucleate topoisomerase
  • Nicking-closing enzyme
  • Relaxing enzyme
  • Swivelase
  • Topoisomerase
  • Type I DNA topoisomerase
  • Untwisting enzyme
  • Omega-protein
  • DNA topoisomerase I

Sequence families

CATH Protein families (Pfam)
PF01751
Domain description: Toprim domain
Occurring in:
  1. DNA topoisomerase 3
1 copy of Pfam domain PF01751 (Toprim domain) in DNA topoisomerase 3 in PDB 1d6m.

PF01131
Domain description: DNA topoisomerase
Occurring in:
  1. DNA topoisomerase 3
1 copy of Pfam domain PF01131 (DNA topoisomerase) in DNA topoisomerase 3 in PDB 1d6m.

CATH InterPro annotations
IPR013497
Domain description: DNA topoisomerase, type IA, central
Occurring in:
  1. DNA topoisomerase 3
IPR006171
Domain description: TOPRIM domain
Occurring in:
  1. DNA topoisomerase 3
IPR005738
Domain description: DNA topoisomerase III
Occurring in:
  1. DNA topoisomerase 3
IPR034144
Domain description: DNA topoisomerase 3-like, TOPRIM domain
Occurring in:
  1. DNA topoisomerase 3
IPR003602
Domain description: DNA topoisomerase, type IA, DNA-binding domain
Occurring in:
  1. DNA topoisomerase 3
IPR023405
Domain description: DNA topoisomerase, type IA, core domain
Occurring in:
  1. DNA topoisomerase 3
IPR003601
Domain description: DNA topoisomerase, type IA, domain 2
Occurring in:
  1. DNA topoisomerase 3
IPR000380
Domain description: DNA topoisomerase, type IA
Occurring in:
  1. DNA topoisomerase 3
IPR013825
Domain description: DNA topoisomerase, type IA, central region, subdomain 2
Occurring in:
  1. DNA topoisomerase 3
IPR023406
Domain description: DNA topoisomerase, type IA, active site
Occurring in:
  1. DNA topoisomerase 3

Structure domains

CATH CATH domains
2.70.20.10
Class: Mainly Beta
Architecture: Distorted Sandwich
Topology: Topoisomerase I; domain 3
Homology: Topoisomerase I, domain 3
Occurring in:
  1. DNA topoisomerase 3
1 copy of CATH domain 2.70.20.10 (Topoisomerase I; domain 3) in DNA topoisomerase 3 in PDB 1d6m.
1.10.460.10
Class: Mainly Alpha
Architecture: Orthogonal Bundle
Topology: Topoisomerase I; domain 2
Homology: Topoisomerase I, domain 2
Occurring in:
  1. DNA topoisomerase 3
1 copy of CATH domain 1.10.460.10 (Topoisomerase I; domain 2) in DNA topoisomerase 3 in PDB 1d6m.
3.40.50.140
Class: Alpha Beta
Architecture: 3-Layer(aba) Sandwich
Topology: Rossmann fold
Homology: Rossmann fold
Occurring in:
  1. DNA topoisomerase 3
1 copy of CATH domain 3.40.50.140 (Rossmann fold) in DNA topoisomerase 3 in PDB 1d6m.
1.10.290.10
Class: Mainly Alpha
Architecture: Orthogonal Bundle
Topology: Topoisomerase I; domain 4
Homology: Topoisomerase I, domain 4
Occurring in:
  1. DNA topoisomerase 3
1 copy of CATH domain 1.10.290.10 (Topoisomerase I; domain 4) in DNA topoisomerase 3 in PDB 1d6m.
SCOP SCOP annotation
56713
Class: Multi-domain proteins (alpha and beta)
Fold: Prokaryotic type I DNA topoisomerase
Superfamily: Prokaryotic type I DNA topoisomerase
Occurring in:
  1. DNA topoisomerase 3
1 copy of SCOP domain 56713 (Prokaryotic type I DNA topoisomerase) in DNA topoisomerase 3 in PDB 1d6m.