Annotation rule MF_01897
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General rule information [?]

Accession MF_01897
Dates 3-MAY-2011 (Created)
11-DEC-2015 (Last updated, Version 5)
Name GyrA
Scope Bacteria
Archaea
Templates P0AES4 (GYRA_ECOLI); P9WG47 (GYRA_MYCTU); P37411 (GYRA_SALTY); O67108 (TOP4A_AQUAE): [Recover all]

Propagated annotation [?]


Identifier, protein and gene names [?]

Identifier
GYRA
Protein name
RecName: Full=DNA gyrase subunit A;
EC=5.99.1.3;
Gene name
gyrA

Comments [?]

Function A type II topoisomerase that negatively supercoils closed circular double-stranded (ds) DNA in an ATP-dependent manner to modulate DNA topology and maintain chromosomes in an underwound state. Negative supercoiling favors strand separation, and DNA replication, transcription, recombination and repair, all of which involve strand separation. Also able to catalyze the interconversion of other topological isomers of dsDNA rings, including catenanes and knotted rings. Type II topoisomerases break and join 2 DNA strands simultaneously in an ATP-dependent manner.
Catalytic activity ATP-dependent breakage, passage and rejoining of double-stranded DNA.
Subunit Heterotetramer, composed of two GyrA and two GyrB chains. In the heterotetramer, GyrA contains the active site tyrosine that forms a transient covalent intermediate with DNA, while GyrB binds cofactors and catalyzes ATP hydrolysis.
Subcellular location Cytoplasm.
Miscellaneous Few gyrases are as efficient as E.coli at forming negative supercoils. Not all organisms have 2 type II topoisomerases; in organisms with a single type II topoisomerase this enzyme also has to decatenate newly replicated chromosomes.
Similarity Belongs to the topoisomerase GyrA/ParC subunit family.

Keywords [?]


Gene Ontology [?]

GO:0005524; Molecular function: ATP binding.
GO:0003677; Molecular function: DNA binding.
GO:0003918; Molecular function: DNA topoisomerase type II (ATP-hydrolyzing) activity.
GO:0006265; Biological process: DNA topological change.
GO:0006261; Biological process: DNA-dependent DNA replication.
GO:0005737; Cellular component: cytoplasm.

Cross-references [?]

Pfam PF03989; DNA_gyraseA_C; 6;
PF00521; DNA_topoisoIV; 1;
TIGRFAMs TIGR01063; GyrA; 1;

Features [?]

From: GYRA_ECOLI (P0AES4)
Key     From     To       Description   Tag   Condition   FTGroup
ACT_SITE     122     122       O-(5'-phospho-DNA)-tyrosine intermediate     Y  
MOTIF     560     566       GyrA-box   motif   Q-[KNRHGA]-[RIT]-[GA]-[GT]-[KRVIQH]-G  

Additional information [?]

Size range 697-1016 amino acids
Related rules None
Fusion None
Comments The degree of DNA negative supercoiling has been studied in very few bacteria, E.coli gyrase is extra efficient compared to other bacteria. The enzyme from Aquifex aeolicus is a topoisomerase IV; the A subunit has lost the GyrA-box and despite its similarity to GyrA does not have the ability to negatively supercoil DNA. Some members of this family contain inteins.