Crystallization and characterization of the prolidase from Pyrococcus furiosus

The prolidase (proline-specific amino dipeptidase) from the hyperthermophil ic archaeon Pyrococcus furiosus has been crystallized. The enzyme has been shown to be a homodimer and to require two Co atoms per subunit for optimum activity. Two crystal forms have been obtained under similar growth condit ions. Both are monoclinic, space group P2(1). Form I has unit-cell paramete rs a = 130.4, b = 97.4, c = 129.9 Angstrom, beta = 118.3 degrees. Form II h as a smaller unit cell, with a = 56.5, b = 97.3, c = 70.0 Angstrom, beta = 97.1 degrees. If the crystal density is assumed to lie near the center of t he normal range then the form I crystals will have four dimers per asymmetr ic unit, whereas the form II crystals will have only one dimer in each asym metric unit. Diffraction data have been recorded from native form I and for m II crystals to resolutions of 3.2 and 1.95 Angstrom, respectively.