DNA gyrase complex

GO:0120217 · Other · Multiprotein complex · Proposed

DNA gyrase complex is a bacterial GyrA2-GyrB2 type IIA topoisomerase complex that uses ATP hydrolysis to introduce negative supercoils into DNA and can also relax positive supercoils. [GO:0120217]

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Components

Component	Type	Part of / acts on	Grounding	Genes	Stoichiometry	Essential	Role
DNA gyrase subunit A	Protein	part of	`InterPro:IPR005743`	gyrA	2 copies per GyrA2-GyrB2 complex		GyrA catalytic subunit of bacterial DNA gyrase, represented twice in the GyrA2-GyrB2 enzyme core. `InterPro:IPR005743` InterPro IPR005743 is a family entry named DNA gyrase, subunit A and is cross-referenced to EC:5.6.2.2. `PDB:6RKU` RCSB maps PDB:6RKU polymer entity 1 to Escherichia coli K-12 DNA gyrase subunit A, UniProtKB:P0AES4.
DNA gyrase subunit B	Protein	part of	`InterPro:IPR011557`	gyrB	2 copies per GyrA2-GyrB2 complex		GyrB subunit of bacterial DNA gyrase, represented twice in the GyrA2-GyrB2 enzyme core. `InterPro:IPR011557` InterPro IPR011557 is a family entry named DNA gyrase, subunit B and is cross-referenced to EC:5.6.2.2. `PDB:6RKU` RCSB maps PDB:6RKU polymer entity 2 to Escherichia coli K-12 DNA gyrase subunit B, UniProtKB:P0AES6.

Canonical examples

NCBITaxon:83333 Escherichia coli K-12 — The source strain for the GyrA and GyrB chains in the complete GyrA2-GyrB2 DNA gyrase-DNA cryo-EM assembly deposited as PDB:6RKU. [PDB:6RKU]

Functions

DNA negative supercoiling activity GO:0034335 — DNA gyrase introduces negative supercoils into DNA and couples DNA topological transformation to ATP hydrolysis.
- GO:0034335 GO:0034335 defines DNA negative supercoiling activity as the catalytic introduction of negative supercoils into DNA.
- GO:0120217 GO:0120217 defines the DNA gyrase complex as a bacterial type IIA topoisomerase that introduces negative supercoils at the expense of ATP hydrolysis.
- PDB:6RKU PDB:6RKU contains two GyrA chains, two GyrB chains, and DNA polymer entities in the Escherichia coli gyrase-DNA nucleoprotein complex.

Mechanism graphs

DNA gyrase introduces negative DNA supercoils (FUNCTION)

The DNA gyrase complex uses its GyrA and GyrB subunits to bind DNA and carry out ATP-dependent negative supercoiling.

Subject	Predicate	Object	Evidence
DNA gyrase complex	enables	DNA negative supercoiling activity	`GO:0120217` GO:0120217 defines the DNA gyrase complex by its ATP-dependent negative-supercoiling activity. `GO:0034335` GO:0034335 is the molecular-function term for DNA negative supercoiling activity.
DNA gyrase subunit A	contributes to	DNA negative supercoiling activity	`InterPro:IPR005743` InterPro IPR005743 identifies the DNA gyrase subunit A family. `PDB:6RKU` PDB:6RKU resolves two GyrA chains with two GyrB chains.
DNA gyrase subunit B	contributes to	DNA negative supercoiling activity	`InterPro:IPR011557` InterPro IPR011557 identifies the DNA gyrase subunit B family. `PDB:6RKU` PDB:6RKU resolves two GyrB chains with two GyrA chains.
DNA gyrase complex	binds	DNA segment	`PDB:6RKU` PDB:6RKU resolves the Escherichia coli GyrA2-GyrB2 protein assembly with DNA polymer entities.
DNA segment	is supercoiled by	DNA negative supercoiling activity	`GO:0034335` GO:0034335 defines DNA negative supercoiling as the catalytic introduction of negative supercoils into a DNA molecule or region.

Evidence

GO:0120217 Gene Ontology cellular-component term for the DNA gyrase complex.
GO:0009330 Gene Ontology cellular-component term for ATP-hydrolyzing DNA topoisomerase type II complexes, the broader class that includes DNA gyrase.
GO:0034335 Gene Ontology molecular-function term for DNA negative supercoiling activity.
GO:0003918 Gene Ontology molecular-function term for ATP-hydrolyzing DNA topoisomerase type II activity.
InterPro:IPR005743 InterPro family for DNA gyrase subunit A.
InterPro:IPR011557 InterPro family for DNA gyrase subunit B.
UniProtKB:P0AES4 UniProtKB reviewed Escherichia coli K-12 entry for DNA gyrase subunit A, GyrA.
UniProtKB:P0AES6 UniProtKB reviewed Escherichia coli K-12 entry for DNA gyrase subunit B, GyrB.
DOI:10.1038/s41467-019-12914-y Vanden Broeck et al. 2019, Cryo-EM structure of the complete E. coli DNA gyrase nucleoprotein complex, Nature Communications.
PMID:31666516 PubMed identifier for Vanden Broeck et al. 2019 as reported by RCSB PDB:6RKU.
PDB:6RKU RCSB Protein Data Bank entry for an Escherichia coli GyrA2-GyrB2 DNA gyrase-DNA cryo-EM structure from Vanden Broeck et al. 2019.

Curation history

2026-09-24T09:27:04Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-24T09:28:11Z codex · EXPANDED_RECORD — Added DNA topoisomerase II parentage, GyrA/GyrB components grounded to exact InterPro families and PDB:6RKU polymer entities, an Escherichia coli K-12 canonical example, DNA negative supercoiling function evidence, and a compact function graph.
2026-09-24T09:38:54Z codex · ADDRESS_REVIEW — #1475: added structured stoichiometry to the GyrA and GyrB component rows to capture the A2B2 DNA gyrase protein assembly described by GO:0120217 and PDB:6RKU.

Source: data/structures/other/dna_gyrase_complex.yaml