The pectate lyase PelI is involved in the degradation of plant tissues by the phytopathogenic bacterium Erwinia chrysanthemi. It has been crystallized from a solution containing PEG 550 in the space group P2(1), with unit-cell parameters a = 61.6, b = 70.7, c = 73.4 A, beta = 112.8 degrees. Crystals diffract to 1.45 A using synchrotron radiation. SAD phases have been computed from a gold-derivative crystal at the wavelength of maximum absorption (L(III) edge).