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Annotation rule MF_00952
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General rule information [?]

Accession MF_00952
Dates 22-MAR-2013 (Created)
19-NOV-2019 (Last updated, Version 9)
Name Topoisom_1_prok
Templates P06612 (TOP1_ECOLI); P9WG49 (TOP1_MYCTU): [Recover all]

Propagated annotation [?]

Identifier, protein and gene names [?]

Protein name
RecName: Full=DNA topoisomerase 1;
AltName: Full=DNA topoisomerase I;
Gene name

Comments [?]

Function Releases the supercoiling and torsional tension of DNA, which is 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 then 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.
Catalytic activity Reaction=ATP-independent breakage of single-stranded DNA, followed by passage and rejoining.; EC=;
Subunit Monomer.
Similarity Belongs to the type IA topoisomerase family.

Keywords [?]

Gene Ontology [?]

GO:0003917; Molecular function: DNA topoisomerase type I (single strand cut, ATP-independent) activity.
GO:0006265; Biological process: DNA topological change.

Cross-references [?]

PS50880; TOPRIM; 1; trigger=PRU00995;
Pfam PF08272; Topo_Zn_Ribbon; 0-2;
PF01131; Topoisom_bac; 1;
PF01751; Toprim; 1;
PF01396; zf-C4_Topoisom; 0-3;
TIGRFAMs TIGR01051; topA_bact; 0-1;
TIGR01057; topA_arch; 0-1;

Features [?]

From: TOP1_ECOLI (P06612)
Key     From     To       Description   Tag   Condition   FTGroup
REGION (Optional)     192     197       Interaction with DNA     S-x-G-R-V-Q  
ACT_SITE     319     319       O-(5'-phospho-DNA)-tyrosine intermediate     Y  
SITE (Optional)     33     33       Interaction with DNA     H  
SITE (Optional)     168     168       Interaction with DNA     R  
SITE (Optional)     169     169       Interaction with DNA     R  
SITE (Optional)     172     172       Interaction with DNA     D  
SITE (Optional)     177     177       Interaction with DNA     Y  
SITE (Optional)     184     184       Interaction with DNA     W  
SITE (Optional)     321     321       Interaction with DNA     R  
SITE (Optional)     507     507       Interaction with DNA     R  

Additional information [?]

Size range 560-1100 amino acids
Related rules None
Fusion None