Crystallization and diffraction to ultrahigh resolution (0.8 Å) of a designed variant of the Rop protein

The Rop protein is the paradigm of a highly regular four-α-helix bundle and as such has been subject to numerous structural and mutagenesis studies. Crystals of a designed Rop variant which establishes a continuous heptad pattern through the bend region have been obtained by a combination of vapour-diffusion and seeding techniques. The crystals diffract to ultrahigh (0.8 Å) resolution using synchrotron radiation and cryogenic conditions.