No "End of History" for Photolyases

In a process called photoreactivation, blue light reverses the chemical damage done to DNA by ultraviolet light. One mediator of this effect is the enzyme CPD photolyase; a second photolyase, (6-4)photolyase, is now reported from Drosophila in a paper in this week's issue (Todo et al. , p. 109 ). In his Perspective, Sancar describes how this discovery defines a family of light-sensitive enzymes that also includes the blue-light receptors of plants and why it represents a reawakening of the photolyase field.