Key Determinants of Rab Specificity

Structures are reported for complexes between Rab27 and the Rab27-binding domains of two molecules involved in successive steps in melanosome transport. Comparison of the Rab27B:Slac2-a (Chavas et al., 2008) and Rab27A:Slp2-a (Kukimoto-Niino et al., 2008) structures with that of the Rab3A:Rabphilin complex gives important clues to the specificity of the interactions.