Abstract :
In a recent article Matthews and coworkers describe a phage T4 lysozyme mutant that incorporates a tandem duplication of an α-helix. Only one repeat can occupy the equivalent wild-type location, however, the structure can be induced to switch to the alternative repeat by modifications to an adjacent turn. The results highlight the interplay between the stabilizing forces of adjacent secondary structures and provide a mechanism for allostery over long distances.
