Gyrase activity and number of copies of the gyrase B subunit gene in Haemophilus influenzae
Gyrase activities in extracts of various strains of Haemophilus influenzae can differ by more than an order of magnitude. Measurements of in vitro activity and copy number indicated that most of these differences arose from variations in the number of copies of the gene for the gyrase B subunit, with some strains containing multicopy plasmids coding for that subunit. The quantitative relationship between gyrase and copy number depended on the mutations in the plasmids and in the host. The possibility that the in vivo gyrase activity did not reflect the in vitro data was explored by measurement of alkaline phosphatase and ATPase activity in the extracts. Alkaline phosphatase activity increased with increasing gyrase activity measured in vitro, but ATPase activity did not. The authors conclude that extra supercoiling enhanced transcription of the alkaline phosphatase gene but not the ATPase gene and that it is unlikely that there is much discrepancy between gyrase activity assayed in vitro and the activity in the cell.
- Research Organization:
- Brookhaven National Lab., Upton, NY
- OSTI ID:
- 5459830
- Journal Information:
- J. Bacteriol.; (United States), Journal Name: J. Bacteriol.; (United States) Vol. 164:2; ISSN JOBAA
- Country of Publication:
- United States
- Language:
- English
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