ALTERED TOPOISOMERASE ACTIVITIES MAY BE INVOLVED IN THE REGULATION OF DNA SUPERCOILING IN AEROBIC-ANAEROBIC TRANSITIONS IN ESCHERICHIA-COLI
ALTERED TOPOISOMERASE ACTIVITIES MAY BE INVOLVED IN THE REGULATION OF DNA SUPERCOILING IN AEROBIC-ANAEROBIC TRANSITIONS IN ESCHERICHIA-COLI
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DOI：
10.1007/bf00925689
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发表时间：
1993-09-22
影响因子：
4.3
通讯作者：
AON, MA
中科院分区：
文献类型：
--
作者：
CORTASSA, S;AON, MA
This study uncovers a new mechanism of regulation of DNA supercoiling operative in vivo upon an aerobic-anaerobic transition in Escherichia coli. Exponentially growing aerobic batch cultures were subjected to a shift to anaerobic conditions. The ratio [ATP]/[ADP] remained essentially constant at 8.5 in the aerobic culture and after a transition to anaerobiosis while DNA supercoiling increased noticeably upon anaerobiosis. This result indicated that the mechanism of regulation of DNA supercoiling by the [ATP]/[ADP] ratio was not operative. The increase in DNA supercoiling was followed by a large decrease in the DNA-relaxing activity of topoisomerase I while gyrase activity remained relatively constant. This decrease in the activity of topoisomerase I is likely to be responsible for the increase in DNA supercoiling.
