Rohman Ali, van Oosterwijk Niels, Dijkstra Bauke W
Laboratory of Biophysical Chemistry, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands.
Acta Crystallogr Sect F Struct Biol Cryst Commun. 2012 May 1;68(Pt 5):551-6. doi: 10.1107/S1744309112011025. Epub 2012 Apr 20.
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.
3-酮类固醇Δ(1)-脱氢酶在类固醇降解的早期步骤中起着关键作用，它通过在其3-酮类固醇底物A环的C1和C2原子之间引入一个双键来实现。来自红平红球菌SQ1的3-酮类固醇Δ(1)-脱氢酶是一种56 kDa的黄素蛋白，采用坐滴气相扩散法在室温下进行结晶。晶体在广泛的pH范围内（从pH 5.5到10.5）的各种缓冲液中生长，但最佳结晶条件是含有2%（v/v）PEG 400、0.1 M HEPES pH 7.5、2.0 M硫酸铵。一个天然晶体的X射线衍射分辨率达到2.0 Å。它属于原始正交空间群P2(1)2(1)2(1)，晶胞参数a = 107.4、b = 131.6、c = 363.2 Å，不对称单位中包含八个分子。该酶的初始结构通过从铂衍生化晶体收集的多波长反常散射（MAD）数据解析得到。
