NEW CRYSTAL FORMS OF ESCHERICHIA-COLI AND SACCHAROMYCES-CEREVISIAE SOLUBLE INORGANIC PYROPHOSPHATASES

We have obtained new crystal forms of Escherichia coil and Saccharomyc es cerevisiae soluble inorganic pyrophosphatase with and without subst rate, competitive inhibitor and divalent cation. They diffract to high er resolution than any forms previously reported. The best E. coli cry stals are in space group R32 with cell dimensions of 111.4 x 111.4 x 7 6.6 Angstrom and diffract to 2.0 Angstrom. The best S. cerevisiae crys tals were grown from a mixture of PEG 1000 and 4000 in the presence of metal ions. They are in space group P2(1)2(1)2(1), have cell dimensio ns of 54.2 x 68.5 x 161.7 Angstrom and diffract to 1.8 Angstrom.