DNA Gyrase A (GyrA)

DNA gyrase A is one of the two essential subunits (GyrA and GyrB) that make up DNA gyrase, a specialized type II topoisomerase found in bacteria. This enzyme is unique for its ability to introduce negative supercoils into closed circular double-stranded DNA in an ATP-dependent manner, a function critical for maintaining proper DNA topology during replication and transcription. The functional enzyme is a heterotetramer composed of two GyrA and two GyrB subunits (A₂B₂ complex). GyrA is responsible for binding and encapsulating DNA and contains the active site tyrosine. DNA gyrase maintains appropriate levels of chromosomal supercoiling required for vital processes. It is an attractive target for antibacterial agents.

Inhibition of DNA gyrase activity, stabilization of cleavage complexes