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SB0111 : DNA topoisomerase I

[ CaMP Format ]

* Basic Information

OrganismHomo sapiens (human)
Protein NamesDNA topoisomerase 1 [Homo sapiens]; DNA topoisomerase 1; type I DNA topoisomerase;; DNA topoisomerase I
Gene NamesTOP1; topoisomerase (DNA) I
Gene Locus20q12-q13.1; chromosome 20
GO FunctionNot available
Entrez Protein Entrez Nucleotide Entrez Gene UniProt OMIM HGNC HPRD KEGG
NP_003277 NM_003286 7150 P11387 126420 HGNC:11986 00535 hsa:7150

* Information From OMIM

Description: DNA topoisomerases I and II (OMIM:126430) catalyze the breaking and rejoining of DNA strands in a way that allows the strands to pass through one another, thus altering the topology of DNA. Type I topoisomerases (EC break a single DNA strand, whereas the type II enzymes break 2 strands of duplex DNA. Several lines of evidence suggest that topoisomerase I normally functions during transcription (summary by D'Arpa et al., 1988).

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* Structure Information

1. Primary Information

Length: 765 aa

Average Mass: 90.725 kDa

Monoisotopic Mass: 90.669 kDa

2. Domain Information

Annotated Domains: interpro / pfam / smart / prosite

Computationally Assigned Domains (Pfam+HMMER):

domain namebeginendscoree-value
Eukaryotic DNA topoisomerase I, catalytic core 1. 5454197.05.4
Eukaryotic DNA topoisomerase I, DNA binding fragment 1. 15618194.013.1
--- cleavage 158 (inside Eukaryotic DNA topoisomerase I, DNA binding fragment 156..181) ---
--- cleavage 183 ---
Eukaryotic DNA topoisomerase I, DNA binding fragment 2. 2154291.08.4
Eukaryotic DNA topoisomerase I, catalytic core 2. 682702200.00.7

3. Sequence Information

Fasta Sequence: SB0111.fasta

Amino Acid Sequence and Secondary Structures (PsiPred):

4. 3D Information

Known Structures in PDB: 1A31 (X-ray; 210 A; A=175-765), 1A35 (X-ray; 250 A; A=175-765), 1A36 (X-ray; 280 A; A=175-765), 1EJ9 (X-ray; 260 A; A=203-765), 1K4S (X-ray; 320 A; A=174-765), 1K4T (X-ray; 210 A; A=174-765), 1LPQ (X-ray; 314 A; A=202-765), 1NH3 (X-ray; 310 A; A=203-765), 1R49 (X-ray; 313 A; A=174-765), 1RR8 (X-ray; 260 A; C=203-765), 1RRJ (X-ray; 230 A; A=201-765), 1SC7 (X-ray; 300 A; A=174-765), 1SEU (X-ray; 300 A; A=174-765), 1T8I (X-ray; 300 A; A=174-765), 1TL8 (X-ray; 310 A; A=174-765)

* Cleavage Information

2 [sites] cleaved by Calpain 2

Source Reference: [PubMed ID: 21086148] Chou SM, Huang TH, Chen HC, Li TK, Calcium-induced cleavage of DNA topoisomerase I involves the cytoplasmic-nuclear shuttling of calpain 2. Cell Mol Life Sci. 2011 Aug;68(16):2769-84. doi: 10.1007/s00018-010-0591-4. Epub

Cleavage sites (±10aa)


Lys158 Lys

P10 P9 P8 P7 P6 P5 P4 P3 P2 P1
P1' P2' P3' P4' P5' P6' P7' P8' P9' P10'

Sequence conservation (by blast)


Lys183 Lys

P10 P9 P8 P7 P6 P5 P4 P3 P2 P1
P1' P2' P3' P4' P5' P6' P7' P8' P9' P10'

Sequence conservation (by blast)

* References

[PubMed ID: 24096022] D'Annessa I, Tesauro C, Wang Z, Arno B, Zuccaro L, Fiorani P, Desideri A, The human topoisomerase 1B Arg634Ala mutation results in camptothecin resistance and loss of inter-domain motion correlation. Biochim Biophys Acta. 2013 Dec;1834(12):2712-21. doi:

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