Effect of cyanide and carbon monoxide on the replication of bacterial DNA in vivo

Abstract

Although the deoxyribonucleoside triphosphate pools in Escherichia coli are known to be equivalent to roughly 1% of the DNA content, we show that either cyanide or carbon monoxide can stop DNA replication by lactate-grown bacteria in less than one thousandth of a generation time. Such KCN-inhibited bacteria can be infected with bacteriophage φX174 and will then undergo further DNA synthesis. We therefore conclude that replication of the bacterial chromosome depends, at all times, upon some CO- and KCN-sensitive reaction which is not required, even in vivo, for the first steps in the synthesis of φX DNA. The possible nature of this reaction is discussed.