Purification, crystallization and preliminary X-ray diffraction studies of Rab11 in complex with Rab11-FIP2.

The small GTPase Rab11 regulates the recycling of endosomes back to the plasma membrane. In its active GTP-bound form, Rab11 binds a novel set of effectors termed the Rab11 family of interacting proteins (Rab11-FIPs) which contain a conserved C-terminal Rab-binding domain (RBD) of unknown structure. Here, a complex of Rab11 with the RBD of Rab11-FIP2 has been purified and crystallized in the trigonal space group P3(1)21, with unit-cell parameters a = 64.99, b = 64.99, c = 112.59 angstroms. Static light-scattering analyses of the molecular weight of the complex in solution are consistent with two copies of Rab11 and two copies of Rab11-FIP2 in the complex.