Crystallization and preliminary X-ray characterization of a thermostable pectate lyase from Thermotoga maritima

Pectate lyase is an enzyme involved in the degradation of the pectate portion of the primary plant cell wall. A recombinant pectate lyase from Thermotoga maritima where three of the four cysteine residues have been mutated (C132I, C156N, C194L) has been crystallized. Crystals of the same morphology and trigonal space group R3 with similar unit-cell parameters were obtained under two different conditions. The first, 0.3 M (NH4)H2PO4 pH 4.2, gave crystals with a maximum size of 0.4 x 0.2 x 0.2 mm in one week that diffracted to a resolution of 1.87 Angstrom and had unit-cell parameters a = b = 80.6, c = 148.8 Angstrom. The second, 0.1 M sodium acetate, 6%(w/v) PEG 4000 pH 6.5, gave the same size crystals in two weeks that diffracted to a resolution of 2.1 A E and had unit-cell parameters a = b = 80.0, c = 150.1 Angstrom.