Generation and use of antibody fragments for structural studies of proteins refractory to crystallization.

With the rapid technological advances in all aspects of macromolecular X-ray crystallography the preparation of diffraction quality crystals has become the rate-limiting step. Crystallization chaperones have proven effective for overcoming this barrier. Here we describe the usage of a Fab chaperone for the crystallization of HIV-1 Rev, a protein that has long resisted all attempts at elucidating its complete atomic structure.