Mus musculus Protein: Top3b
Summary
InnateDB Protein IDBP-137528.6
Last Modified 2014-10-13 [Report errors or provide feedback]
Gene Symbol Top3b
Protein Name topoisomerase (DNA) III beta
Synonyms
Species Mus musculus
Ensembl Protein ENSMUSP00000023465
InnateDB Gene IDBG-137526 (Top3b)
Protein Structure
UniProt Annotation
Function Releases the supercoiling and torsional tension of DNA introduced during the DNA replication and transcription by transiently cleaving and rejoining one strand of the DNA duplex. Introduces a single-strand break via transesterification at a target site in duplex DNA. The scissile phosphodiester is attacked by the catalytic tyrosine of the enzyme, resulting in the formation of a DNA-(5'-phosphotyrosyl)-enzyme intermediate and the expulsion of a 3'-OH DNA strand. The free DNA strand than undergoes passage around the unbroken strand thus removing DNA supercoils. Finally, in the religation step, the DNA 3'-OH attacks the covalent intermediate to expel the active-site tyrosine and restore the DNA phosphodiester backbone (By similarity). Possesses negatively supercoiled DNA relaxing activity. {ECO:0000250}.
Subcellular Localization
Disease Associations
Tissue Specificity Highly expressed in testis.
Comments
Interactions
Number of Interactions This gene and/or its encoded proteins are associated with 0 experimentally validated interaction(s) in this database.
They are also associated with 11 interaction(s) predicted by orthology.
Predicted by orthology
Total 11 [view]
Gene Ontology

Molecular Function
Accession GO Term
GO:0003677 DNA binding
GO:0003916 DNA topoisomerase activity
GO:0003917 DNA topoisomerase type I activity
GO:0005524 ATP binding
GO:0044822 poly(A) RNA binding
Biological Process
GO:0006265 DNA topological change
GO:0007059 chromosome segregation
Cellular Component
GO:0000793 condensed chromosome
GO:0005634 nucleus
Protein Structure and Domains
PDB ID MGI:1333803
InterPro IPR000380 DNA topoisomerase, type IA
IPR003601 DNA topoisomerase, type IA, domain 2
IPR003602 DNA topoisomerase, type IA, DNA-binding
IPR006171 Toprim domain
IPR013497 DNA topoisomerase, type IA, central
IPR023405 DNA topoisomerase, type IA, core domain
PFAM PF01751
PF13662
PF01131
PRINTS PR00417
PIRSF
SMART SM00436
SM00437
SM00493
TIGRFAMs
Post-translational Modifications
Modification
Cross-References
SwissProt Q9Z321
PhosphoSite PhosphoSite-Q9Z321
TrEMBL Q3UJF5
UniProt Splice Variant
Entrez Gene 21976
UniGene Mm.326089
RefSeq NP_035754
MGI ID
MGI Symbol Top3b
OMIM
CCDS CCDS27990
HPRD
IMGT
EMBL AB013603 AC166832 AK144709 AK146475 BC031723 CH466521
GenPept AAH31723 BAA34227 BAE26026 BAE27200 EDK97432