Protein–RNA interactions: Getting into the major groove

RNA–protein interactions are involved in many cellular processes, including information storage and transfer, catalysis and transcriptional activation. Our structural knowledge of these interactions at atomic resolution is based on X-ray crystallographic and nuclear magnetic resonance (NMR) studies (for a review see [1]). The crystal structures of a number of RNA–protein complexes have been reported, including those formed between three aminoacyl-tRNA synthetases and their cognate tRNAs, the RNA-binding domain of the U1A ribonucleoprotein and its target RNA sequence, and the bacteriophage MS2 coat protein and a specific RNA operator fragment. The NMR studies have been of small RNAs bound to individual amino acids or peptides.