Makokha Moses, Huang Yuanpeng Janet, Montelione Gaetano, Edison Arthur S, Barbar Elisar
Department of Biochemistry and Biophysics, Ohio University, Athens, 45701-2979, USA.
Protein Sci. 2004 Mar;13(3):727-34. doi: 10.1110/ps.03462204. Epub 2004 Feb 6.
The structure of Drosophila LC8 pH-induced monomer has been determined by NMR spectroscopy using the program AutoStructure. The structure at pH 3 and 30 degrees C is similar to the individual subunits of mammalian LC8 dimer with the exception that a beta strand, which crosses between monomers to form an intersubunit beta-sheet in the dimer, is a flexible loop with turnlike conformations in the monomer. Increased flexibility in the interface region relative to the rest of the protein is confirmed by dynamic measurements based on (15)N relaxation. Comparison of the monomer and dimer structures indicates that LC8 is not a domain swapped dimer.
果蝇LC8 pH诱导单体的结构已通过使用AutoStructure程序的核磁共振光谱法确定。在pH 3和30摄氏度下的结构与哺乳动物LC8二聚体的单个亚基相似,不同之处在于,在二聚体中跨单体形成亚基间β折叠的一条β链,在单体中是具有类似转角构象的柔性环。基于(15)N弛豫的动力学测量证实,相对于蛋白质的其余部分,界面区域的柔性增加。单体和二聚体结构的比较表明,LC8不是结构域交换二聚体。