Chemical & Engineering News published a brief news story today on Ashworth et al., which appeared in the June 1st issue of Nature. In that paper, the authors showed that computational protein design could be used to alter the specificity of the homing endonuclease I-MsoI. The redesigned enzyme was highly active and it cleaved the new recognition sequence about 10,000 times more effectively (in vitro) than the wild-type enzyme.

Earlier this year, David Liu's laboratory demonstrated that it was possible to use directed evolution to modify the specificity of another homing endonuclease (I-SceI), but Ashworth et al. is the first paper in which computational protein design was successfully used to modify the specificity of a homing endonuclease.

The authors say that "the method should be generalizable to any protein–DNA interface redesign problem: for example, the reprogramming of transcription factor binding specificity" and they believe that "[t]he use and refinement of the computational modelling and design strategies described here should ... [enable them to design] novel proteins [that are] able to recognize and cleave any desired DNA site with high specificity for targeted genomics applications."

Joshua

Joshua Finkelstein (Associate Editor, Nature)