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HAMAP rule MF_00952

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General rule information [?]

Accession MF_00952
Dates 22-MAR-2013 (Created)
10-OCT-2023 (Last updated, Version 11)
Name Topoisom_1_prok
Scope(s) Bacteria
Template(s) P06612 (TOP1_ECOLI); P9WG49 (TOP1_MYCTU); [ Recover all ]
Triggered by HAMAP; MF_00952 (Get profile general information and statistics)

Propagated annotation [?]

Identifier, protein and gene names [?]

Identifier TOP1
Protein name RecName: Full=DNA topoisomerase 1;
AltName: Full=DNA topoisomerase I;
Gene name Name=topA;

Comments [?]

FUNCTIONReleases 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=;
SIMILARITYBelongs 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 [?]

PROSITE PS00396; TOPO_IA_1; 1;
PROSITE PS52039; TOPO_IA_2; 1;
Pfam PF08272; Topo_Zn_Ribbon; 0-2;
Pfam PF01131; Topoisom_bac; 1;
Pfam PF01751; Toprim; 1;
Pfam PF01396; zf-C4_Topoisom; 0-3;
NCBIfam TIGR01051; topA_bact; 0-1;
NCBIfam TIGR01057; topA_arch; 0-1;

Features [?]

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

Additional information [?]

Size range 560-1100 amino acids
Related rules None
Fusion Nter: None Cter: None

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