CRYSTALLIZATION AND PRELIMINARY-X-RAY STUDIES OF SIALIDASE L FROM THELEECH MACROBDELLA-DECORA

Functional monomeric 83 kDa sialidase L, a NeuAc alpha 2-->3Gal-specif ic sialidase from Macrobdella leech, was expressed in Escherichia coli and readily crystallized by a macroseeding technique. The crystal bel ongs to space group P1 with unit-cell parameters a = 46.4, b = 69.3, c = 72.5 Angstrom, alpha = 113.5 beta = 95.4 and gamma = 107.3 degrees. There is one molecule per unit cell, giving a V-m = 2.4 Angstrom(3) D a(-1) and a solvent content of 40%. Native and mercury-derivative data sets were collected to 2.0 Angstrom resolution. Threading and molecul ar-replacement calculations confirmed the existence of a bacterial sia lidase-like domain.