Induced-fit motion of a lid loop involved in catalysis in alginate lyase A1-III.

The structures of two mutants (H192A and Y246F) of a mannuronate-specific alginate lyase, A1-III, from Sphingomonas species A1 complexed with a tetrasaccharide substrate [4-deoxy-L-erythro-hex-4-ene-pyranosyluronate-(mannuronate)(2)-mannuronic acid] were determined by X-ray crystallography at around 2.2 Å resolution together with the apo form of the H192A mutant. The final models of the complex forms, which comprised two monomers (of 353 amino-acid residues each), 268-287 water molecules and two tetrasaccharide substrates, had R factors of around 0.

Crystallization and preliminary crystallographic analysis of endo-1,3-beta-glucanase from Arthrobacter sp.

Endo-1,3-beta-glucanases hydrolyze internal 1,3-beta-glucosyl linkages. The endo-1,3-beta-glucanase from Arthrobacter sp. was crystallized by the hanging-drop vapour-diffusion method.

Structural basis of a fungal galectin from Agrocybe cylindracea for recognizing sialoconjugate.

Galectin from an edible fungus Agrocybe cylindracea (ACG) has a strong preference for N-acetylneuraminyl lactose (NeuAcalpha2-3lactose). The sugar recognition mechanism of ACG was explored by the X-ray crystallographic analyses of ligand-free ACG, and its complex with lactose, 3'-sulfonyl lactose and NeuAcalpha2-3lactose. The refined structure shows that ACG is a "proto"-type galectin composed of a beta-sandwich of two antiparallel sheets, each with six strands, in contrast to the five and six strands in animal galectins.