Chir Jiun-Ly, Liao Jiahn-Haur, Lin Yu-Ching, Wu Shih-Hsiung
Institute of Biological Chemistry, Academia Sinica, Nankang, Taipei, Taiwan.
Biochem Biophys Res Commun. 2009 May 15;382(4):762-5. doi: 10.1016/j.bbrc.2009.03.109. Epub 2009 Mar 24.
Previous studies on the N-terminal domain of Lon proteases have not clearly identified its function. Here we constructed randomly chosen N-terminal-truncated mutants of the Lon protease from Brevibacillus thermoruber WR-249 to elucidate the structure-function relationship of this domain. Mutants lacking amino acids from 1 to 247 of N terminus retained significant peptidase and ATPase activities, but lost approximately 90% of protease activity. Further truncation of the protein resulted in the loss of all three activities. Mutants lacking amino acids 246-259 or 248-256 also lost all activities and quaternary structure. Our results indicated that amino acids 248-256 (SEVDELRAQ) are important for the full function of the Lon protease.
先前对Lon蛋白酶N端结构域的研究尚未明确其功能。在此，我们构建了来自嗜热短芽孢杆菌WR-249的Lon蛋白酶随机选择的N端截短突变体，以阐明该结构域的结构-功能关系。缺失N端1至247个氨基酸的突变体保留了显著的肽酶和ATP酶活性，但丧失了约90%的蛋白酶活性。蛋白质的进一步截短导致所有三种活性丧失。缺失246-259或248-256氨基酸的突变体也丧失了所有活性和四级结构。我们的结果表明，248-256氨基酸（SEVDELRAQ）对Lon蛋白酶的完整功能很重要。
