Fig. 1.

Structural representation of oxidized A₂B₂–GAPDH complexed with NADP. (a) Schematic representation of the crystallographic model: a tetramer whose chains are named O, R, P, and Q, and a dimer ST, which generated a second tetramer by a crystallographic two-fold axis coincident with the molecular axis P. (b) Ribbon model of a single tetramer of oxidized A₂B₂–GAPDH. The coenzyme molecules, the sulfate ions of each subunit, and the cysteines of the CTE are represented as balls and sticks. (c) Superimposition of oxidized A₂B₂–GAPDH (gold) and recombinant A₄–GAPDH (red) tetramers (14), both complexed with NADP. The dimension of the tetramer along R-axis was measured between the C_α atoms of residues O86 and P86 or residues R86 and Q86. Helices are represented as cylinders and β-strands are represented as arrows. The images were produced by MOLSCRIPT (31) and rendered by Raster3D (32).