REGULATORY GTPASES

The past year has witnessed a tremendous increase in our understanding of the structures and interactions of the GTPases. The highlights inc lude crystal structures oi Cor subunits, as well as the first complex between a GTPase (Rap1A) and an effector molecule (c-Raf1 Ras-binding domain). In the field of elongation factors (EFs), three very importan t structures have been determined: EF-G, the ternary complex of EF-Tu . GTP with aminoacyl-tRNA, and the EF-TU EF-Ts complex.