Initiation of Deoxyribonucleic Acid Replication in Escherichia coli B/r: Chronology of Events and Transcriptional Control of Initiation

Abstract

Three processes necessary for the initiation of deoxyribonucleic acid replication have been separated in time in synchronously growing Escherichia coli B/r. One can be inhibited with 2 μg of chloramphenicol per ml and occurs about 20 min prior to initiation. A second step, occurring 5 to 10 min prior to initiation, is sensitive to 4 to 30 μg of chloramphenicol per ml. A third process occurs at the time of initiation and can be inhibited with rifampin. The experiments suggest that transcription itself, or the synthesis of a relatively small ribonucleic acid, is required for initiation of replication.