Tuesday, November 01, 2011

DNA stretching by origin recognition protein

In E. coli (and other bacteria), the origin of replication (known as oriC) is recognized by the DnaA proteins.  In this recent paper in Nature [here], structural studies show that the binding of DnaA molecules to the oriC DNA region leads to the stretching of the DNA molecule, and the stabilization of single stranded DNA, which appears to be part of the process for assembling the DNA replication complex. Yet another cool molecular machine.

The red structure is the single-stranded DNA, the other colors are the proteins.  Can you determine whether DnaA is primarily composed of beta-sheets or alpha-helices?

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