Gene: TOP1 (DNA topoisomerase I) Homo sapiens
Symbol: TOP1
Name: DNA topoisomerase I
Description: This gene encodes a DNA topoisomerase, an enzyme that controls and alters the topologic states of DNA during transcription. This enzyme catalyzes the transient breaking and rejoining of a single strand of DNA which allows the strands to pass through one another, thus altering the topology of DNA. This gene is localized to chromosome 20 and has pseudogenes which reside on chromosomes 1 and 22. [provided by RefSeq, Jul 2008]
Type: protein-coding
RefSeq Status: REVIEWED
Also known as: DNA topoisomerase 1; Scl-70 antigen; TOPI; topoisomerase (DNA) I; type I DNA topoisomerase
Mus musculus (house mouse) : Top1 (topoisomerase (DNA) I)  MGI  Alliance
Rattus norvegicus (Norway rat) : Top1 (DNA topoisomerase I)  Alliance
Chinchilla lanigera (long-tailed chinchilla) : Top1 (DNA topoisomerase I)
Pan paniscus (bonobo/pygmy chimpanzee) : TOP1 (DNA topoisomerase I)
Canis lupus familiaris (dog) : TOP1 (DNA topoisomerase I)
Ictidomys tridecemlineatus (thirteen-lined ground squirrel) : Top1 (DNA topoisomerase I)
Sus scrofa (pig) : TOP1 (DNA topoisomerase I)
more info ...
Related Pseudogenes: TOP1P1   TOP1P2  
Allele / Splice: See ClinVar data
Latest Assembly: GRCh38 - Human Genome Assembly GRCh38
Human AssemblyChrPosition (strand)SourceGenome Browsers
GRCh382041,028,818 - 41,124,487 (+)NCBIGRCh38GRCh38hg38GRCh38
GRCh372039,657,462 - 39,753,127 (+)NCBIGRCh37GRCh37hg19GRCh37
Build 362039,090,876 - 39,186,541 (+)NCBINCBI36hg18NCBI36
Build 342039,090,875 - 39,186,541NCBI
Celera2036,368,028 - 36,463,696 (+)NCBI
Cytogenetic Map20q12NCBI
HuRef2036,395,468 - 36,491,177 (+)NCBIHuRef
CHM1_12039,561,887 - 39,657,539 (+)NCBICHM1_1
JBrowse: View Region in Genome Browser (JBrowse)

Disease Annotations
Gene-Chemical Interaction Annotations
Gene Ontology Annotations
Molecular Pathway Annotations
References - curated
References - uncurated


Comparative Map Data
Position Markers
miRNA Target Status


Nucleotide Sequences
Protein Sequences
Clinical Variants

Additional Information

External Database Links
Nomenclature History
More on TOP1
Alliance Gene
Ensembl Gene
JBrowse: hg19 hg38
HGNC Report
NCBI Genome Data Viewer

CRRD Object Information
CRRD ID: 733198
Created: 2004-01-12
Species: Homo sapiens
Last Modified: 2019-06-11
Status: ACTIVE


RGD is funded by grant HL64541 from the National Heart, Lung, and Blood Institute on behalf of the NIH.