O'Farrell Heather C, Musayev Faik N, Scarsdale J Neel, Wright H Tonie, Rife Jason P
Department of Biochemistry, Virginia Commonwealth University, Richmond, VA 23298-0133, USA.
Acta Crystallogr D Biol Crystallogr. 2003 Aug;59(Pt 8):1490-2. doi: 10.1107/s0907444903011855. Epub 2003 Jul 23.
The bacterial enzyme KsgA catalyzes the transfer of a total of four methyl groups from S-adenosylmethionine (SAM) to two adjacent adenosines in 16S rRNA. These modified adenosines are universally conserved in all species of eubacteria, eukaryotes and archaebacteria studied. Recombinant KsgA from Escherichia coli was overexpressed as a His-tagged fusion protein and purified. The recombinant protein was crystallized using PEG 4000 as a precipitant. The crystals belong to space group C2 and diffract X-rays to a resolution of 1.9 A. The unit-cell parameters are a = 173.9, b = 38.4, c = 83.0 A, beta = 90.0 degrees. Structure determination using the molecular-replacement method is at the early stages of refinement.
细菌酶KsgA催化总共四个甲基从S-腺苷甲硫氨酸（SAM）转移至16S核糖体RNA中两个相邻的腺苷上。在所有已研究的真细菌、真核生物和古细菌物种中，这些修饰的腺苷都是普遍保守的。来自大肠杆菌的重组KsgA作为带有His标签的融合蛋白被过量表达并纯化。使用聚乙二醇4000作为沉淀剂使重组蛋白结晶。晶体属于空间群C2，X射线衍射分辨率为1.9埃。使用分子置换法进行结构测定正处于精修的早期阶段。
