What is it about?

The initiator of replication ,DnaA, is a pure product of the imagination of Francois Jacob and Sydney Brenner. In order to demonasrate its existense, I had to isolate the mutants of dnaA. The paper descirbes my struggling for their isolation of temperature sensitive mutants,from which ilnitiation mutants,dnaA, were screened. Surprisingly the mutants,dnaA, were found to reinitiate replication after gamma ray irradiation.

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Why is it important?

Once the existence of the initiator was proven in E.coli, other groups looked for the same sort of protein in other bacteria as wells in higher multicellular organisms. Thus DnaA type of replication initiator is found in almost all oragnisms.


The chromosome replication is one of the signs of tumorigenesis. Therefore it is important to look for the inhibitor for cancer therapy. ,It is also important to emphasize that,in this case, the imagination direted the resaerch to attain the goal but not the chance.

Dr masamichi kohiyama
Universite Paris deiderot; Inst.J.MOnod

Read the Original

This page is a summary of: Research on DnaA in the early days, Research in Microbiology, December 2020, Elsevier, DOI: 10.1016/j.resmic.2020.11.004.
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