Crystallization and preliminary diffraction studies of malate dehydrogenase from Streptomyces aureofaciens.

Purified malate dehydrogenase (MDH) of Streptomyces aureofaciens was crystallized either in the absence or in the presence of NADH or NADPH coenzymes by hanging-drop vapour-diffusion method. An X-ray study has shown, that MDH crystals belong to space group C2221 with unit-cell parameters A = 53.2 A, b = 104.6 A, c = 520.0 A, α = β = γ = 90° , MDH-NADH crystals to space group C2 with unit-cell parameters A = 51.5 A, b = 51.5 A, c = 256 A, α = β = γ = 90 , and MDH-NADPH crystals to space group C2221 with unit-cell parameters A = 72, A b = 72 A, c = 520 A, α = β = γ = 90° . The crystal of native MDH diffracted to 2.1 A resolution.