RNA binding strategies of ribosomal proteins

Structures of a number of ribosomal proteins have now been determined by cr ystallography and NMR, though the complete structure of a ribosomal protein -rRNA complex has yet to be solved. However, some ribosomal protein structu res show strong similarity to well-known families of DNA or RNA binding pro teins for which structures in complex with cognate nucleic acids are availa ble. Comparison of the known nucleic acid binding mechanisms of these non-r ibosomal proteins with the most highly conserved surfaces of similar riboso mal proteins suggests ways in which the ribosomal proteins may be binding R NA. Three binding motifs, found in four ribosomal proteins so far, are cons idered here: homeodomain-like cc-helical proteins (L11), OB fold proteins ( S1 and S17) and RNP consensus proteins (S6), These comparisons suggest that ribosomal proteins combine a small number of fundamental strategies to dev elop highly specific RNA recognition sites.