Tsai Ying-Der, Chin Ko-Hsin, Shr Hui-Lin, Gao Fei Philip, Lyu Ping-Chiang, Wang Andrew H-J, Chou Shan-Ho
Institute of Biochemistry, National Chung-Hsing University, Taichung 40227, Taiwan.
Acta Crystallogr Sect F Struct Biol Cryst Commun. 2006 Oct 1;62(Pt 10):999-1002. doi: 10.1107/S1744309106035433. Epub 2006 Sep 30.
CN-hydrolase superfamily proteins are involved in a wide variety of non-peptide carbon-nitrogen hydrolysis reactions, producing some important natural products such as auxin, biotin, precursors of antibiotics etc. These reactions all involve attack on a cyano or carbonyl carbon by a conserved novel catalytic triad Glu-Lys-Cys through a thiol acylenzyme intermediate. However, classification into the CN-hydrolase superfamily based on sequence similarity alone is not straightforward and further structural data are necessary to improve this categorization. Here, the cloning, expression, crystallization and preliminary X-ray analysis of XC1258, a CN-hydrolase superfamily protein from the plant pathogen Xanthomonas campestris (Xcc), are reported. The SeMet-substituted XC1258 crystals diffracted to a resolution of 1.73 A. They are orthorhombic and belong to space group P2(1)2(1)2, with unit-cell parameters a = 143.8, b = 154.63, c = 51.3 A, respectively.
腈水解酶超家族蛋白参与多种非肽碳氮水解反应，产生一些重要的天然产物，如生长素、生物素、抗生素前体等。这些反应均涉及一个保守的新型催化三联体Glu-Lys-Cys通过硫醇酰基酶中间体对氰基或羰基碳的攻击。然而，仅基于序列相似性将其分类到腈水解酶超家族并不简单，还需要进一步的结构数据来改进这种分类。本文报道了来自植物病原菌野油菜黄单胞菌（Xcc）的腈水解酶超家族蛋白XC1258的克隆、表达、结晶及初步X射线分析。硒代甲硫氨酸取代的XC1258晶体衍射分辨率达到1.73 Å。它们为正交晶系，属于空间群P2(1)2(1)2，晶胞参数分别为a = 143.8、b = 154.63、c = 51.3 Å。
