【摘要】 Nir2蛋白具有多个结构域,在生物体中可能发挥多种生理功能.通过MAD软件对大肠杆菌BL21（plys）原核表达的Nir2蛋白碳端进行的晶体结构分析结果显示,硒蛋氨酸取代蛋白晶体及未取代蛋白晶体同属空间群P2₁2₁2₁（晶胞参数a=109.468 ,b=120.621 ,c=70.315 ,α=β=Υ=90°）,分辨率分别为2.2和2.7.一个不对称单位含有三个分子,含水量为48%.Nir2蛋白碳端由C片层和N片层构成,其中C片层与钙ATPase的催化区域P相似,N片层为许多不相关的功能性蛋白所共有.研究证明二者之间的静电作用是影响Nir2蛋白碳端与Pyk2 FERM区域结合的主要因素.更多还原

【Abstract】 Nir2 is a multiple-domain protein and may play several biological roles.The crystal structure is solved by using MAD method of Nir2 C-terminal domain overexpressed in bacteria E.coli BL21（plys）. Both unsubstituted and Selenomethionine-suhstituted crystals belong to space group P2₁2₁2₁ （a=109.468 A,b=120.621 ,c=70.315 ,α=β=γ90°） and diffract to 2.2 A and 2.7 A,respectively.There are three molecules in one asymmetrical unit and solvent content was 48%.The structure reveals that Nir2 C-terminal domain consists of N lobe and C lobe,the C lobe is similar to the catalytic domain P of calcium ATPase,and N lobe can be found in many functionally unrelated proteins.The results suggest that electrostatic interaction between them is the key factor for the binding of Nir2 C-terminal domain to Pyk2 FERM domain.更多还原