HAMAP rule MF_00953
General rule information
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Accession | MF_00953 |
Dates | 27-MAR-2013 (Created) 26-JAN-2023 (Last updated, Version 12) |
Name | Topoisom_3_prok |
Scope | Bacteria |
Template | P14294 (TOP3_ECOLI) |
Triggered by |
Propagated annotation
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Identifier, protein and gene names
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Identifier |
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Protein name |
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Gene name |
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Comments
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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=5.6.2.1; |
case <FTGroup:1>
Cofactor | Mg(2+) Note: Binds two Mg(2+) per subunit. |
else case <FTGroup:2>
Cofactor | Mg(2+) |
end case
Similarity | Belongs to the type IA topoisomerase family. |
Keywords
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case <FTGroup:1> or <FTGroup:2>
end case
Gene Ontology
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GO:0003917; Molecular function: DNA topoisomerase type I (single strand cut, ATP-independent) activity.
case <FTGroup:1> or <FTGroup:2>
GO:0000287; Molecular function: magnesium ion binding.
end case
GO:0006265; Biological process: DNA topological change.
Cross-references
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PROSITE | PS00396; TOPOISOMERASE_I_PROK; 1; |
PS50880; TOPRIM; 1; trigger=PRU00995; | |
Pfam | PF01131; Topoisom_bac; 1; |
PF01751; Toprim; 1; | |
PRINTS | PR00417; PRTPISMRASEI; 1; |
TIGRFAMs | TIGR01056; topB; 1; |
Features
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From: TOP3_ECOLI (P14294) | ||||||||||||
Key | From | To | Description | Tag | Condition | FTGroup | ||||||
REGION (Optional) | 194 | 199 | Interaction with DNA | [SN]-x-G-R-V-Q | ||||||||
ACT_SITE | 328 | 328 | O-(5'-phospho-DNA)-tyrosine intermediate | Y |
case <OC:Pseudomonadota>
else
BINDING | 7 | 7 | /ligand="Mg(2+)" /ligand_id="ChEBI:CHEBI:18420" /ligand_note="catalytic | E | 2 | |||||||
BINDING | 103 | 103 | /ligand="Mg(2+)" /ligand_id="ChEBI:CHEBI:18420" /ligand_note="catalytic | D | 2 |
end case
Additional information
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Size range | 610-765 amino acids |
Related rules | None |
Fusion | None |