Crystallization and preliminary X-ray analysis of the RAD protein from Antirrhinum majus

An 8 kDa proteolytic fragment of the A. majus RADIALIS protein was crystallized and X-ray data were collected to 2 Å resolution. Crystals of the RADIALIS protein from Antirrhinum majus were grown by vapour diffusion after limited proteolysis. Mass spectrometry indicated that an 8 kDa fragment had been crystallized corresponding to the predicted MYB DNA-binding domain. X-ray data collected at room temperature were consistent with tetragonal symmetry, whereas data collected at 100 K using crystals cryoprotected by supplementing the mother liquor with ethylene glycol conformed to orthorhombic symmetry. It was subsequently shown that crystals soaked in cryoprotectants that were 'osmolality-matched' to the mother liquor retained tetragonal symmetry. Using these crystals, X-ray data were collected in-house to a maximum resolution of 2 Å