High pressure modulation of Escherichia coli DNA gyrase activity.

Elevated pressures greater than 551 bar were found to inhibit the DNA supercoiling activity of Escherichia coli DNA gyrase. A large fraction of the inhibitory effect could be reproduced by preincubation of the enzyme at high pressure prior to enzymatic assay at 1 bar. It is proposed that elevated pressure influences gyrase structure, most likely by promoting the dissociation of its subunits, however, it is also possible that effects on enzyme activity exist.