DNA Gyrase Subunit B (GyrB)

DNA gyrase subunit B (GyrB) is one of the two essential subunits that make up bacterial DNA gyrase, a type II topoisomerase unique to prokaryotes. The enzyme is a heterotetramer composed of two GyrA and two GyrB subunits. DNA gyrase introduces negative supercoils into closed circular double-stranded DNA in an ATP-dependent manner, which is crucial for maintaining the underwound state of bacterial chromosomes and facilitating processes such as replication, transcription, recombination, and repair. GyrB is absent in mammals, making it an attractive target for antibacterial drug development due to its essential role in bacterial viability without off-target effects on human cells. Several antibiotics target either the A or B subunit; novobiocin specifically inhibits the ATP-binding site on GyrB. Recent studies have identified novel small-molecule inhibitors targeting this domain using structure-based virtual screening approaches—these compounds show promising activity against bacterial strains resistant to existing drugs like ciprofloxacin or novobiocin.

Inhibition of ATP binding and hydrolysis; stabilization of specific residues in its active site