AC   MF_01897;
DC   Protein; auto
TR   HAMAP; MF_01897; -; 1; level=0
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Names: GyrA
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ID   GYRA
DE   RecName: Full=DNA gyrase subunit A;
DE            EC=5.6.2.2;
GN   Name=gyrA;
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CC   -!- FUNCTION: A type II topoisomerase that negatively supercoils closed
CC       circular double-stranded (ds) DNA in an ATP-dependent manner to
CC       modulate DNA topology and maintain chromosomes in an underwound state.
CC       Negative supercoiling favors strand separation, and DNA replication,
CC       transcription, recombination and repair, all of which involve strand
CC       separation. Also able to catalyze the interconversion of other
CC       topological isomers of dsDNA rings, including catenanes and knotted
CC       rings. Type II topoisomerases break and join 2 DNA strands
CC       simultaneously in an ATP-dependent manner.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=ATP-dependent breakage, passage and rejoining of double-
CC         stranded DNA.; EC=5.6.2.2;
CC   -!- SUBUNIT: Heterotetramer, composed of two GyrA and two GyrB chains. In
CC       the heterotetramer, GyrA contains the active site tyrosine that forms a
CC       transient covalent intermediate with DNA, while GyrB binds cofactors
CC       and catalyzes ATP hydrolysis.
CC   -!- SUBCELLULAR LOCATION: Cytoplasm.
CC   -!- MISCELLANEOUS: Few gyrases are as efficient as E.coli at forming
CC       negative supercoils. Not all organisms have 2 type II topoisomerases;
CC       in organisms with a single type II topoisomerase this enzyme also has
CC       to decatenate newly replicated chromosomes.
CC   -!- SIMILARITY: Belongs to the type II topoisomerase GyrA/ParC subunit
CC       family.
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DR   Pfam; PF03989; DNA_gyraseA_C; 6; trigger=no
DR   Pfam; PF00521; DNA_topoisoIV; 1; trigger=no
DR   NCBIfam; TIGR01063; GyrA; 1; trigger=no
DR   PROSITE; PS52040; TOPO_IIA; 1; trigger=yes
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KW   ATP-binding
KW   Cytoplasm
KW   DNA-binding
KW   Isomerase
KW   Nucleotide-binding
KW   Topoisomerase
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GO   GO:0005524; F:ATP binding
GO   GO:0003677; F:DNA binding
GO   GO:0003918; F:DNA topoisomerase type II (double strand cut, ATP-hydrolyzing) activity
GO   GO:0006265; P:DNA topological change
GO   GO:0006261; P:DNA-templated DNA replication
GO   GO:0005737; C:cytoplasm
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FT   From: GYRA_ECOLI (P0AES4)
FT   ACT_SITE        122
FT                   /note="O-(5'-phospho-DNA)-tyrosine intermediate"
FT   Condition: Y
FT   MOTIF           560..566
FT                   /note="GyrA-box"
FT   Tag: motif; Condition: Q-[KNRHGA]-[RIT]-[GA]-[GT]-[KRVIQH]-G
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Size: 697-1016;
Related: None;
Template: P0AES4; P9WG47; P37411; O67108;
Scope:
 Bacteria
 Archaea
Fusion:
 Nter: None
 Cter: None
Duplicate: None
Plasmid: 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.
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# Revision 1.13 2023/10/10
//