As you can see, the RecA story has turned out to be quite interesting and there is plenty more to talk about. But since this blog is not called “The Land of RecA,” I think I’ll give this subject a rest for now. However, as a parting gift, I offer up this bit of research which highlights just what a sophisticated little device we have here:

Now, Julia Cox, Oleg Tsodikov, and Michael Cox present evidence indicating that filaments of the bacterial RecA protein, long known for their role in homologous recombination and DNA repair, have properties reminiscent of a molecular motor as well.

[…]

The authors note that there are approximately six RecA molecules per helical turn in a RecA filament. They propose that the RecA molecules hydrolyzing ATP at any given moment are aligned in a “stripe” that runs along the side of the filament. This stripe of ATP hydrolysis moves around the fiber in a repeating pattern of six steps. At the 5′ end of the fiber, ATP hydrolysis leads to RecA release. But in the middle of the fiber, it could work as a rotary motor, with the power to wind or unwind DNA and drive strand invasion through difficult passages of damaged DNA.

Sweet. Here’s a picture of the stripe along the RecA filament, making it easier to envision the coordinated ATP hydrolysis being converted into rotary motion within the tube that winds or unwinds the DNA.

And for those interested, here is the study: Organized Unidirectional Waves of ATP Hydrolysis within a RecA Filament