Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain
the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in
Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles
and JavaScript.
SH2 domains mediate protein-protein interactions and are involved in a wide range of intracellular signalling events, but what is the basis of their specificity?
By binding a peptide consisting of all D-amino acids calmodulin appears to have broken one of the central tenets of biochemistry; that protein interactions are stereospecific.