Finding the Missing Code of RNA Recognition by PUF Proteins

Pumilio and FBF homology (PUF) proteins represent highly promising candidates for engineering sequence-specific RNA recognition, but were only known to recognize G, A, and U, significantly limiting applications. Two groups (Filipovska et al., 2011; Dong et al., 2011) have now reported the discovery of the cytosine-recognition code for PUF proteins.