gyrase

noun

gyr·​ase ˈjī-ˌrās 

: a bacterial enzyme that catalyzes the breaking and rejoining of bonds linking adjacent nucleotides in circular DNA to generate supercoiled DNA helices

Word History

Etymology

gyr- + -ase

First Known Use

1976, in the meaning defined above

Medical Definition

gyrase

noun

gy·​rase ˈjī-ˌrās, -ˌrāz 

: a bacterial enzyme that is a topoisomerase which catalyzes the ATP-dependent breaking and rejoining of double-strands in circular DNA to generate negative supercoils that twist in the opposite direction as the turns in the original helices

Note: The supercoils introduced by the bacterial gyrase help to relieve the torsional stress in the circular DNA strands that is a consequence of the unwinding of the DNA during replication.