Crystallization and preliminary X-ray study of pig liver dihydropyrimidinedehydrogenase

Dihydropyrimidine dehydrogenase catalyzes the first and rate-limiting react ion in pyrimidine catabolism. The enzyme contains one FMN, one FAD and four Fe-S clusters per subunit of 1025 amino acids as prosthetic groups. It is also the major determinant of bioavailability and toxicity of 5-fluorouraci l, a chemotherapeutic agent widely used in the treatment of solid tumors. C rystals of this enzyme diffracting to at least 2.5 Angstrom have been obtai ned by the hanging-drop vapour-diffusion method and belong to space group P 2(1) (unit-cell parameters a = 82.0, b = 159.3, c = 163.6 Angstrom, beta = 96.1 degrees), with two homodimers per asymmetric unit.