Bamford V, Dobbin P S, Lee S C, Reilly A, Powell A K, Richardson D J, Hemmings A M
Centre for Metalloprotein Spectroscopy and Biology, School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, England.
Acta Crystallogr D Biol Crystallogr. 1999 Jun;55(Pt 6):1222-5. doi: 10.1107/s0907444999004114.
The fumarate reductase of Escherichia coli and other bacteria is a membrane-bound enzyme consisting of four subunits. A soluble periplasmic 64 kDa tetrahaem flavocytochrome c3 from Shewanella frigidimarina NCIMB400 which possesses a catalytic fumarate reductase activity has been crystallized. The crystals belong to space group P212121 with unit-cell parameters a = 72.4, b = 110.1, c = 230.2 A. Assuming a molecular dimer in the asymmetric unit, the crystals contain 65% solvent and, when cryocooled to 100 K, the crystals diffract to at least 3.0 A resolution. The crystals, however, display an inherent lack of isomorphism and the plausibility of a MAD phasing experiment has therefore been investigated by measuring the iron K absorption edge from a single crystal.
大肠杆菌和其他细菌的延胡索酸还原酶是一种由四个亚基组成的膜结合酶。来自嗜冷希瓦氏菌NCIMB400的一种可溶性周质64 kDa四血红素黄素细胞色素c3已被结晶，该细胞色素c3具有催化延胡索酸还原酶活性。晶体属于空间群P212121，晶胞参数a = 72.4、b = 110.1、c = 230.2 Å。假设不对称单位中有一个分子二聚体，晶体含有65%的溶剂，当冷冻至100 K时，晶体衍射分辨率至少为3.0 Å。然而，这些晶体表现出固有的同晶型缺乏，因此通过测量单晶的铁K吸收边研究了MAD相位实验的可行性。
