Subunit composition, crystallization and preliminary crystallographic studies of the Desulfovibrio gigas aldehyde oxidoreductase containing molybdenum and [2Fe‐2S] centers

The Desulfovibrio gigas aldehyde oxidoreductase contains molybdenum bound to a pterin cofactor and [2Fe‐2S] centers. The enzyme was characterized by SDS/PAGE, gel‐filtration and analytical ultracentrifugation experiments. It was crystallized at 4°C, pH 7.2, using isopropanol and MgCl ₂ as precipitants. The crystals diffract beyond 0.3‐nm (3.0‐Å) resolution and belong to space group P6 ₁ 22 or its enantiomorph, with cell dimensions a=b= 14.45 nm and c= 16.32 nm. There is one subunit/asymmetric unit which gives a packing density of 2.5 × 10 ⁻³ nm ³ /Da (2.5 Å ³ /Da), consistent with the experimental crystal density, p= 1.14 g/cm ³ . One dimer (approximately 2 × 100 kDa) is located on a crystallographic twofold axis.