Molecular and General Genetics MGG

, Volume 155, Issue 2, pp 219–225 | Cite as

Regulation of the dnaA product in Escherichia coli

  • Flemming G. Hansen
  • Knud V. Rasmussen


When an E. coli mutant (CRT46, dnaA46), thermosensitive in the initiation of DNA replication, grows at intermediate temperatures its DNA/mass ratio is somewhat lower than normal, but the cells possess an excess of initiation capacity, which can be expressed in the absence of proteins synthesis and lead to the accumulation of anomalously high amounts of DNA. A shift-up in temperature causes inhibition of initiation, and at the same time the production of initiation capacity is accelerated. After a shift-down in temperature initiation is released but the production of capacity is inhibited. The initiation capacity is thermolabile.

The simplest explanation of these observations is that the dnaA product has a dual role: a positive function as an initiator of replication and a negative control function in its own synthesis.


Negative Control Protein Synthesis Control Function Positive Function Dual Role 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer-Verlag 1977

Authors and Affiliations

  • Flemming G. Hansen
    • 1
  • Knud V. Rasmussen
    • 1
  1. 1.University Institute of MicrobiologyCopenhagen KDenmark

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