Skip Header

You are using a version of Internet Explorer that may not display all features of this website. Please upgrade to a modern browser.
Contribute Send feedback
Read comments (?) or add your own

O95985 (TOP3B_HUMAN) Reviewed, UniProtKB/Swiss-Prot

Last modified April 16, 2014. Version 132. Feed History...

Clusters with 100%, 90%, 50% identity | Documents (5) | Third-party data text xml rdf/xml gff fasta
to top of pageNames·Attributes·General annotation·Ontologies·Alt products·Sequence annotation·Sequences·References·Cross-refs·Entry info·DocumentsCustomize order

Names and origin

Protein namesRecommended name:
DNA topoisomerase 3-beta-1

EC=5.99.1.2
Alternative name(s):
DNA topoisomerase III beta-1
Gene names
Name:TOP3B
Synonyms:TOP3B1
OrganismHomo sapiens (Human) [Reference proteome]
Taxonomic identifier9606 [NCBI]
Taxonomic lineageEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresPrimatesHaplorrhiniCatarrhiniHominidaeHomo

Protein attributes

Sequence length862 AA.
Sequence statusComplete.
Protein existenceEvidence at transcript level

General annotation (Comments)

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.

Catalytic activity

ATP-independent breakage of single-stranded DNA, followed by passage and rejoining.

Tissue specificity

Isoform 1 is found in testis, heart and skeletal muscle. A 4 kb transcript which probably represents isoform 2 is found in thymus, kidney and pancreas. Ref.1

Sequence similarities

Belongs to the type IA topoisomerase family.

Contains 1 Toprim domain.

Sequence caution

The sequence BAA20009.1 differs from that shown. Reason: Erroneous gene model prediction.

Alternative products

This entry describes 3 isoforms produced by alternative splicing. [Align] [Select]
Isoform 1 (identifier: O95985-1)

This isoform has been chosen as the 'canonical' sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry.
Isoform 2 (identifier: O95985-2)

The sequence of this isoform differs from the canonical sequence as follows:
     703-730: GMGCNECTHPSCQHSLSMLGIGQCVECE → GECSHSLLSTGSCSLFSVPTPALHQAGL
     731-862: Missing.
Isoform 3 (identifier: O95985-3)

The sequence of this isoform differs from the canonical sequence as follows:
     703-707: GMGCN → VVPCV
     708-862: Missing.

Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

Chain1 – 862862DNA topoisomerase 3-beta-1
PRO_0000145192

Regions

Domain3 – 153151Toprim

Sites

Active site3361O-(5'-phospho-DNA)-tyrosine intermediate By similarity

Natural variations

Alternative sequence703 – 73028GMGCN…CVECE → GECSHSLLSTGSCSLFSVPT PALHQAGL in isoform 2.
VSP_006525
Alternative sequence703 – 7075GMGCN → VVPCV in isoform 3.
VSP_006527
Alternative sequence708 – 862155Missing in isoform 3.
VSP_006528
Alternative sequence731 – 862132Missing in isoform 2.
VSP_006526
Natural variant3651D → N. Ref.6
Corresponds to variant rs9610728 [ dbSNP | Ensembl ].
VAR_052591

Sequences

Sequence LengthMass (Da)Tools
Isoform 1 [UniParc].

Last modified May 1, 1999. Version 1.
Checksum: 75532827856CFF8F

FASTA86296,662
        10         20         30         40         50         60 
MKTVLMVAEK PSLAQSIAKI LSRGSLSSHK GLNGACSVHE YTGTFAGQPV RFKMTSVCGH 

        70         80         90        100        110        120 
VMTLDFLGKY NKWDKVDPAE LFSQAPTEKK EANPKLNMVK FLQVEGRGCD YIVLWLDCDK 

       130        140        150        160        170        180 
EGENICFEVL DAVLPVMNKA HGGEKTVFRA RFSSITDTDI CNAMACLGEP DHNEALSVDA 

       190        200        210        220        230        240 
RQELDLRIGC AFTRFQTKYF QGKYGDLDSS LISFGPCQTP TLGFCVERHD KIQSFKPETY 

       250        260        270        280        290        300 
WVLQAKVNTD KDRSLLLDWD RVRVFDREIA QMFLNMTKLE KEAQVEATSR KEKAKQRPLA 

       310        320        330        340        350        360 
LNTVEMLRVA SSSLGMGPQH AMQTAERLYT QGYISYPRTE TTHYPENFDL KGSLRQQANH 

       370        380        390        400        410        420 
PYWADTVKRL LAEGINRPRK GHDAGDHPPI TPMKSATEAE LGGDAWRLYE YITRHFIATV 

       430        440        450        460        470        480 
SHDCKYLQST ISFRIGPELF TCSGKTVLSP GFTEVMPWQS VPLEESLPTC QRGDAFPVGE 

       490        500        510        520        530        540 
VKMLEKQTNP PDYLTEAELI TLMEKHGIGT DASIPVHINN ICQRNYVTVE SGRRLKPTNL 

       550        560        570        580        590        600 
GIVLVHGYYK IDAELVLPTI RSAVEKQLNL IAQGKADYRQ VLGHTLDVFK RKFHYFVDSI 

       610        620        630        640        650        660 
AGMDELMEVS FSPLAATGKP LSRCGKCHRF MKYIQAKPSR LHCSHCDETY TLPQNGTIKL 

       670        680        690        700        710        720 
YKELRCPLDD FELVLWSSGS RGKSYPLCPY CYNHPPFRDM KKGMGCNECT HPSCQHSLSM 

       730        740        750        760        770        780 
LGIGQCVECE SGVLVLDPTS GPKWKVACNK CNVVAHCFEN AHRVRVSADT CSVCEAALLD 

       790        800        810        820        830        840 
VDFNKAKSPL PGDETQHMGC VFCDPVFQEL VELKHAASCH PMHRGGPGRR QGRGRGRARR 

       850        860 
PPGKPNPRRP KDKMSALAAY FV 

« Hide

Isoform 2 [UniParc].

Checksum: 8CC2903C7C4304E6
Show »

FASTA73082,123
Isoform 3 [UniParc].

Checksum: BE43F9D46B50AA85
Show »

FASTA70779,839

References

« Hide 'large scale' references
[1]"A new human topoisomerase III that interacts with SGS1 protein."
Ng S.-W., Liu Y., Hasselblatt K.T., Mok S.C., Berkowitz R.S.
Nucleic Acids Res. 27:993-1000(1999) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 1), ALTERNATIVE SPLICING, TISSUE SPECIFICITY.
[2]"One-megabase sequence analysis of the human immunoglobulin lambda gene locus."
Kawasaki K., Minoshima S., Nakato E., Shibuya K., Shintani A., Schmeits J.L., Wang J., Shimizu N.
Genome Res. 7:250-261(1997) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].
[3]Hanai R., Li W., Wang J.C.
Submitted (AUG-1997) to the EMBL/GenBank/DDBJ databases
Cited for: NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 1).
[4]Riou J.F., Goulaouic H., Grondard L.
Submitted (FEB-1999) to the EMBL/GenBank/DDBJ databases
Cited for: NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 1).
[5]"A genome annotation-driven approach to cloning the human ORFeome."
Collins J.E., Wright C.L., Edwards C.A., Davis M.P., Grinham J.A., Cole C.G., Goward M.E., Aguado B., Mallya M., Mokrab Y., Huckle E.J., Beare D.M., Dunham I.
Genome Biol. 5:R84.1-R84.11(2004) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] (ISOFORM 1).
[6]"The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC)."
The MGC Project Team
Genome Res. 14:2121-2127(2004) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] (ISOFORM 1), VARIANT ASN-365.
Tissue: Skin.
+Additional computationally mapped references.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ
AF053082 mRNA. Translation: AAD15791.1.
D87012 Genomic DNA. Translation: BAA20009.1. Sequence problems.
AF017146 mRNA. Translation: AAD01614.1.
AF125216 mRNA. Translation: AAD29670.1.
CR456596 mRNA. Translation: CAG30482.1.
BC002432 mRNA. Translation: AAH02432.1.
RefSeqNP_001269041.1. NM_001282112.1.
NP_001269042.1. NM_001282113.1.
NP_003926.1. NM_003935.4.
XP_005261868.1. XM_005261811.1.
UniGeneHs.436401.

3D structure databases

ProteinModelPortalO95985.
SMRO95985. Positions 3-633.
ModBaseSearch...
MobiDBSearch...

Protein-protein interaction databases

BioGrid114452. 13 interactions.
IntActO95985. 3 interactions.
MINTMINT-1458306.
STRING9606.ENSP00000349705.

PTM databases

PhosphoSiteO95985.

Proteomic databases

PaxDbO95985.
PRIDEO95985.

Protocols and materials databases

DNASU8940.
StructuralBiologyKnowledgebaseSearch...

Genome annotation databases

EnsemblENST00000357179; ENSP00000349705; ENSG00000100038. [O95985-1]
ENST00000398793; ENSP00000381773; ENSG00000100038. [O95985-1]
GeneID8940.
KEGGhsa:8940.
UCSCuc002zvs.3. human. [O95985-1]

Organism-specific databases

CTD8940.
GeneCardsGC22M022309.
HGNCHGNC:11993. TOP3B.
HPAHPA032134.
MIM603582. gene.
neXtProtNX_O95985.
PharmGKBPA36674.
GenAtlasSearch...

Phylogenomic databases

eggNOGCOG0550.
HOGENOMHOG000184378.
HOVERGENHBG059857.
InParanoidO95985.
KOK03165.
OMAPITPMKA.
OrthoDBEOG7RBZ7N.
PhylomeDBO95985.
TreeFamTF105288.

Gene expression databases

ArrayExpressO95985.
BgeeO95985.
CleanExHS_TOP3B.
GenevestigatorO95985.

Family and domain databases

Gene3D1.10.460.10. 2 hits.
2.70.20.10. 2 hits.
3.40.50.140. 1 hit.
InterProIPR000380. Topo_IA.
IPR003601. Topo_IA_2.
IPR023406. Topo_IA_AS.
IPR013497. Topo_IA_cen.
IPR013824. Topo_IA_cen_sub1.
IPR013825. Topo_IA_cen_sub2.
IPR023405. Topo_IA_core_domain.
IPR003602. Topo_IA_DNA-bd.
IPR006171. Toprim_domain.
[Graphical view]
PANTHERPTHR11390. PTHR11390. 1 hit.
PfamPF01131. Topoisom_bac. 1 hit.
PF01751. Toprim. 1 hit.
[Graphical view]
PRINTSPR00417. PRTPISMRASEI.
SMARTSM00437. TOP1Ac. 1 hit.
SM00436. TOP1Bc. 1 hit.
SM00493. TOPRIM. 1 hit.
[Graphical view]
SUPFAMSSF56712. SSF56712. 1 hit.
PROSITEPS00396. TOPOISOMERASE_I_PROK. 1 hit.
PS50880. TOPRIM. 1 hit.
[Graphical view]
ProtoNetSearch...

Other

GeneWikiTOP3B.
GenomeRNAi8940.
NextBio33622.
PROO95985.
SOURCESearch...

Entry information

Entry nameTOP3B_HUMAN
AccessionPrimary (citable) accession number: O95985
Secondary accession number(s): A0M8Q3, Q9BUP5
Entry history
Integrated into UniProtKB/Swiss-Prot: May 30, 2000
Last sequence update: May 1, 1999
Last modified: April 16, 2014
This is version 132 of the entry and version 1 of the sequence. [Complete history]
Entry statusReviewed (UniProtKB/Swiss-Prot)
Annotation programChordata Protein Annotation Program
DisclaimerAny medical or genetic information present in this entry is provided for research, educational and informational purposes only. It is not in any way intended to be used as a substitute for professional medical advice, diagnosis, treatment or care.

Relevant documents

SIMILARITY comments

Index of protein domains and families

MIM cross-references

Online Mendelian Inheritance in Man (MIM) cross-references in UniProtKB/Swiss-Prot

Human polymorphisms and disease mutations

Index of human polymorphisms and disease mutations

Human entries with polymorphisms or disease mutations

List of human entries with polymorphisms or disease mutations

Human chromosome 22

Human chromosome 22: entries, gene names and cross-references to MIM