DNA gyrase subunit A

Protein at a glance

Function

A type II topoisomerase that negatively supercoils closed circular double-stranded (ds) DNA in an ATP-dependent manner to maintain chromosomes in an underwound state (PubMed:12051842, PubMed:18642932, PubMed:186775, PubMed:19060136, PubMed:19965760, PubMed:20356737, PubMed:22457353, PubMed:23294697, PubMed:3031051, PubMed:7811004, PubMed:9148951). This makes better substrates for topoisomerase IV (ParC and ParE) which is the main enzyme that unlinks newly replicated chromosomes in E.coli (PubMed:9334322). Gyrase catalyzes the interconversion of other topological isomers of dsDNA rings, including catenanes (PubMed:22457352). Relaxes negatively supercoiled DNA in an ATP-independent manner (PubMed:337300). E.coli gyrase has higher supercoiling activity than many other bacterial gyrases; at comparable concentrations E.coli gyrase introduces more supercoils faster than M.tuberculosis gyrase, while M.tuberculosis gyrase has higher decatenation than supercoiling activity compared to E.coli (PubMed:22457352). E.coli makes 15% more negative supercoils in pBR322 plasmid DNA than S.typhimurium; the S.typhimurium GyrB subunit is toxic in E.coli, while the E.coli copy can be expressed in S.typhimurium even though the 2 subunits have 777/804 residues identical (PubMed:17400739). The enzymatic differences between E.coli gyrase and topoisomerase IV are largely due to the GyrA C-terminal domain (approximately residues 524-841) and specifically the GyrA-box (PubMed:16332690, PubMed:8962066)

Bacterial DNA gyrase inhibitor

Acts on a complex — shared with gyrB · 1 of 2 recorded protein targets — narrow recorded profile

COMPLETED · via Ciprofloxacin · NCT01344512