CRYSTALLIZATION AND PRELIMINARY-X-RAY DIFFRACTION STUDIES ON ADP-RIBOSYLATION FACTOR 1

ADP-ribosylation factor 1 (ARF-1) is a member of a family of small G-p roteins that regulate both intracellular vesicle transport and phospho lipase D activity Crystals of ARF-1 suitable for X-ray diffraction ana lysis have been grown in the presence of GDP by the hanging drop vapou r diffusion method. Crystals grow in space group C2 with cell dimensio ns a = 122.36 Angstrom, b = 45.01 Angstrom, 91.96 Angstrom and beta = 133.62 degrees and diffract to at least 2.3 Angstrom resolution. A sec ond crystal form has been characterized (space group C2, a = 69.70 Ang strom, b = 45.25 Angstrom, c = 60.45 Angstrom, beta = 109.6 degrees) b ut does not grow reproducibly.