Purification, crystallization and preliminary X-ray crystallographic analysis of 3-ketosteroid Δ1-dehydrogenase from Rhodococcus erythropolis SQ1.
3-Ketosteroid Δ(1)-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 Δ(1)-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 P2(1)2(1)2(1), 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.
Laboratory of Biophysical Chemistry, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands.
Ali
A
Rohman
Niels
N
van Oosterwijk
Bauke W
BW
Dijkstra
D003460:Crystallization; D018360:Crystallography, X-Ray; D004795:Enzyme Stability; D008958:Models, Molecular; D010088:Oxidoreductases / Q000737:chemistry* / Q000302:isolation & purification; D017434:Protein Structure, Tertiary; D012240:Rhodococcus / Q000201:enzymology*
D010088:Oxidoreductases; C022656:3-oxosteroid delta(1) dehydrogenase