Liu Xiao Yan, Lei Jian, Liu Xiang, Su Xiao Dong, Li Lanfen
Peking University, Beijing, People's Republic of China.
Acta Crystallogr Sect F Struct Biol Cryst Commun. 2009 Mar 1;65(Pt 3):282-4. doi: 10.1107/S1744309109003856. Epub 2009 Feb 26.
The speA gene in Bacillus subtilis encodes arginine decarboxylase, which catalyzes the conversion of arginine to agmatine. Arginine decarboxylase is an important enzyme in polyamine metabolism in B. subtilis. In order to further illustrate the catalytic mechanism of arginine decarboxylase by determining the three-dimensional structure of the enzyme, the speA gene was amplified from B. subtilis genomic DNA and cloned into the expression vector pET-28a(+). SpeA was expressed in Escherichia coli and purified to homogeneity by nickel-chelation chromatography followed by size-exclusion chromatography. High-quality crystals were obtained using the hanging-drop vapour-diffusion method at 289 K. The best crystal diffracted to 2.0 A resolution and belonged to space group P2(1), with unit-cell parameters a = 86.4, b = 63.3 c = 103.3 A, beta = 113.9 degrees .
枯草芽孢杆菌中的speA基因编码精氨酸脱羧酶，该酶催化精氨酸转化为胍丁胺。精氨酸脱羧酶是枯草芽孢杆菌多胺代谢中的一种重要酶。为了通过确定该酶的三维结构进一步阐明精氨酸脱羧酶的催化机制，从枯草芽孢杆菌基因组DNA中扩增speA基因，并将其克隆到表达载体pET-28a(+)中。SpeA在大肠杆菌中表达，并通过镍螯合色谱随后进行尺寸排阻色谱纯化至均一性。在289 K下使用悬滴气相扩散法获得了高质量的晶体。最佳晶体衍射至2.0 Å分辨率，属于空间群P2(1)，晶胞参数a = 86.4，b = 63.3，c = 103.3 Å，β = 113.9°。
