Crystals of a mutant form of ribosomal protein L22 rendering bacterial ribosomes resistant to erythromycin

A mutant form of Thermus thermophilus ribosomal protein L22 responsible for erythromycin resistance has been overexpressed in Escherichia coli, purified to homogeneity and crystallized using the hanging-drop vapour-diffusion technique. While several different crystallization conditions were found, only one set of conditions yielded crystals suitable for X-ray diffraction analysis. These crystals grow as thick plates, with unit-cell parameters a = 31.8, b = 86.59, c = 38.96 Angstrom, beta = 104.47 degrees. The crystals belong to the space group P2(1) and diffract to 1.8 Angstrom resolution. On the basis of density calculations, two monomers are predicted per asymmetric unit (V-M = 2.06 Angstrom (3) Da(-1)), with a solvent content of 40%.