A0A2K8SMH9 · A0A2K8SMH9_9NOSO

Function

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.

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.

Catalytic activity

  • ATP-dependent breakage, passage and rejoining of double-stranded DNA.
    EC:5.6.2.2 (UniProtKB | ENZYME | Rhea)

Cofactor

Mg2+ (UniProtKB | Rhea| CHEBI:18420 )

Mn2+ (UniProtKB | Rhea| CHEBI:29035 )

Ca2+ (UniProtKB | Rhea| CHEBI:29108 )

Note: Binds two Mg2+ per subunit. The magnesium ions form salt bridges with both the protein and the DNA. Can also accept other divalent metal cations, such as Mn2+ or Ca2+.

Features

Showing features for binding site, site.

TypeIDPosition(s)Description
Binding site432Mg2+ 1 (UniProtKB | ChEBI); catalytic
Site457Interaction with DNA
Site460Interaction with DNA
Binding site506Mg2+ 2 (UniProtKB | ChEBI)
Binding site506Mg2+ 1 (UniProtKB | ChEBI); catalytic
Binding site508Mg2+ 2 (UniProtKB | ChEBI)

GO annotations

AspectTerm
Cellular Componentchromosome
Cellular Componentcytoplasm
Molecular FunctionATP binding
Molecular FunctionDNA binding
Molecular FunctionDNA topoisomerase type II (double strand cut, ATP-hydrolyzing) activity
Molecular Functionmetal ion binding
Biological ProcessDNA topological change
Biological ProcessDNA-templated DNA replication

Keywords

Enzyme and pathway databases

Names & Taxonomy

Protein names

  • Recommended name
    DNA gyrase subunit B
  • EC number

Gene names

    • Name
      gyrB
    • ORF names
      COO91_02583

Organism names

Accessions

  • Primary accession
    A0A2K8SMH9

Proteomes

Subcellular Location

Keywords

Interaction

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.

Family & Domains

Features

Showing features for domain.

TypeIDPosition(s)Description
Domain426-541Toprim

Sequence similarities

Belongs to the type II topoisomerase GyrB family.

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    645
  • Mass (Da)
    71,960
  • Last updated
    2018-04-25 v1
  • Checksum
    2531EB8EEA81BF83
MTSSYSADQIQVLEGLEAVRKRPGMYIGTTGPRGLHHLVYEVVDNSIDEALAGHCTHIEVDINADGSVTVTDDGRGIPVDTHSRTGKSALETVMTVLHAGGKFGGGGYKVSGGLHGVGISVVNALSEVVEVTVWRDKKVHLQRYERGIPVSELQVKPYKEARSGTSVTFKPDTQIFTTSIEFDYITLSGRLRELAYLNAGVKITFTDHRLELLKSDTPKVESYNYKGGIKEYIAYMNREKQPLHEEIIYVQGERNNVQVEVSLQWCTDAYTDNVLGFANNIRTVDGGTHLEGLKAVLTRTLNAIARKRNKIKENEPNLSGEHVREGLTAVISVKVPDPEFEGQTKTKLGNTEVRGIVDSLVGEVLTEYLEFHPAIADSILDKAIQAFKAAEAARHARELVRRKSVLESSPLPGKLADCSSRDPSESEIFIVEGDSAGGSAKQGRDRRTQAILPLRGKILNIEKTDDAKIYKNNEVQSLITALGLGVKGDEFDSTQLRYHRIVIMTDADVDGAHIRTLLLTFFYRYQRALIEQGFIYIACPPLFKVERGRNHEYCYSDREKDQAIAKFPANANYTIQRFKGLGEMMPQQLWDTTMNPETRKMKQVEIEDAAEADRIFTILMGDRVAPRREFIETYGSKLNFTDLDI

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
CP024785
EMBL· GenBank· DDBJ
AUB36662.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

Disclaimer

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