Synthesis of mRNA of malB operons at specific stages in the cell cycle of Escherichia coli.

The mRNA synthesis of the malB operons was examined using synchronous cultures of Escherichia coli. mRNA of the malB operons were synthetized in cell cycle-specific manners different from the bulk mRNA synthesis. The synthesis occurred in two stages during a cell cycle, one in the middle of the cycle and the other at the time slightly before cell division. Identification of the species of mRNA revealed that the malK-lamB operon was preferably transcribed in the former stage of the cycle while a major fraction of mRNA of the malE-malF operon was synthesized in the later stage.