A fucose-specific lectin from Aleuria aurantia was crystallized in its native form and was also cocrystallized with HgCl(2). Crystallization was performed using the sitting-drop vapour-diffusion method with ammonium sulfate as a precipitant. Both the Hg-free native crystals and the Hg cocrystals belong to the hexagonal space group P6(5)22. The unit-cell parameters for the Hg-free form are a = 84.0, c = 250.1 A and for the Hg cocrystals are a = 83.9, c = 254.3 A. Both forms of the crystals diffract X-rays to 2.3 A resolution and are suitable for high-resolution crystal structure determination. Initial phasing was successfully performed by the MAD method using the Hg cocrystals and the electron density obtained was good enough for model building.

In several organisms that form fruit bodies, the synthesis of lectins is developmentally regulated. Aleuria aurantia is an ascomycete that forms a fruit body known as orange peel mushroom. To find whether the mycelia of this organism synthesize a lectin, mycelial isolates were obtained from a wild fruit body by spore germination and regeneration from a fragment of the fruit body. The isolates were identified as A. aurantia by analysis of their DNA. The mycelial isolates synthesized a lectin with the same properties as those of fruit-body lectin in terms of subunit molecular mass, immunochemical reactivity, binding specificity for L-fucose, and N-terminal amino acid sequence. Vegetatively growing mycelia synthesized as much lectin as the fruit body, so such synthesis was not developmentally regulated, unlike some other organisms that form fruit bodies.