Liu P, Ewis H E, Huang Y J, Lu C D, Tai P C, Weber I T
Department of Biology, Molecular Basis of Disease Program, Georgia State University, Atlanta, Georgia 30303, USA.
Acta Crystallogr Sect F Struct Biol Cryst Commun. 2007 Dec 1;63(Pt 12):1003-7. doi: 10.1107/S1744309107054127. Epub 2007 Nov 21.
The sodA gene of Bacillus subtilis was expressed in Escherichia coli, purified and crystallized. The crystal structure of MnSOD was solved by molecular replacement with four dimers per asymmetric unit and refined to an R factor of 21.1% at 1.8 A resolution. The dimer structure is very similar to that of the related enzyme from B. anthracis. Larger structural differences were observed with the human MnSOD, which has one less helix in the helical domain and a longer loop between two beta-strands and also showed differences in three amino acids at the intersubunit interface in the dimer compared with the two bacterial MnSODs. These structural differences can be exploited in the design of drugs that selectively target the Bacillus enzymes.
枯草芽孢杆菌的sodA基因在大肠杆菌中表达、纯化并结晶。通过分子置换法解析了锰超氧化物歧化酶（MnSOD）的晶体结构，每个不对称单元有四个二聚体，在1.8埃分辨率下精修至R因子为21.1%。二聚体结构与炭疽芽孢杆菌的相关酶非常相似。与人类MnSOD相比，观察到更大的结构差异，人类MnSOD在螺旋结构域中少一个螺旋，两条β链之间的环更长，并且在二聚体的亚基间界面处的三个氨基酸与两种细菌MnSOD也存在差异。这些结构差异可用于设计选择性靶向芽孢杆菌酶的药物。
