Acta Crystallographica Section D

Biological Crystallography

Volume 57, Part 7 (July 2001)

crystallization papers

Acta Cryst. (2001). D57, 1042-1045 [ doi:10.1107/S0907444901007284 ]

Characterization and crystallization of a novel Sarcocystis muris lectin, SML-2

J. J. Müller, E.-C. Müller, T. Montag, N. Zyto, B. Löschner, H. Klein, U. Heineman and A. Otto

Abstract: A novel lectin (SML-2) consisting of 138 amino acids was isolated from cyst merozoites of Sarcocystis muris and sequenced by Edman degradation and mass spectrometry. All 12 cysteinyl residues are involved in disulfide bridges, four of which are attributed to a characteristic pattern of cysteines as found in the so-called PAN-module superfamily. Crystals of SML-2 diffracting to 2.1 Å resolution at a synchrotron were grown by the hanging-drop vapour-diffusion technique. They belong to the space group P2₁2₁2₁, with unit-cell parameters a = 53.6, b = 128.8, c = 158.2 Å and eight molecules in the asymmetric unit. SML-2 cocrystallized with Au galactose results in two different crystal forms. The first form is isomorphous with the native crystals and the second form adopts space group C222₁, with unit-cell parameters a = 74.7, b = 82.0, c = 131.0 Å, and diffracts to 2.4 Å at a rotating-anode X-ray generator.

Keywords: lectins; Sarcocystis muris.