Purification, crystallization and preliminary X‐ray crystallographic analysis of 3‐ketosteroid Δ
Abstract:3‐Ketosteroid Δ1‐dehydrogenase plays a crucial role in the early steps of steroid degradation by introducing a double bond between the C1 and C2 atoms of the A‐ring of its 3‐ketosteroid substrates. The 3‐ketosteroid Δ1‐dehydrogenase from Rhodococcus erythropolis SQ1, a 56 kDa flavoprotein, was crystallized using the sitting‐drop vapour‐diffusion method at room temperature. The crystals grew in various buffers over a wide pH range (from pH 5.5 to 10.5), but the best crystallization condition consisted of 2%(v/v) PEG 400, 0.1 M HEPES pH 7.5, 2.0 M ammonium sulfate. A native crystal diffracted X‐rays to 2.0 Å resolution. It belonged to the primitive orthorhombic space group P212121, with unit‐cell parameters a = 107.4, b = 131.6, c = 363.2 Å, and contained eight molecules in the asymmetric unit. The initial structure of the enzyme was solved using multi‐wavelength anomalous dispersion (MAD) data collected from a Pt‐derivatized crystal.
Document Type: Research Article
Publication date: 2012-05-01