PRELIMINARY CRYSTALLOGRAPHIC ANALYSIS OF 4-OXALOCROTONATE TAUTOMERASEREVEALS THE OLIGOMERIC STRUCTURE OF THE ENZYME

Crystals of recombinant 4-oxalocrotonate tautomerase from Pseudomonas sp. strain CF600 have been obtained in a form suitable for X-ray analy sis. The enzyme is a highly efficient catalyst and is unusual in that it consists of subunits of only 62 amino acids. It crystallises is the triclinic space group, P1, with unit cell dimensions a = 39.6 Angstro m, b = 51.5 Angstrom, c = 51.6 Angstrom, alpha = 60.0 degrees, beta = 81.4 degrees, gamma = 69.6 degrees. The crystals diffract to beyond 1. 9 Angstrom resolution and are stable to irradiation with X-rays. Preli minary crystallographic data are not consistent with the previously su ggested pentameric structure, but indicate that the complex is in fact a hexamer with 32 symmetry