Numata O, Takemasa T, Takagi I, Hirono M, Hirano H, Chiba J, Watanabe Y
Institute of Biological Sciences, University of Tsukuba, Ibaraki, Japan.
Biochem Biophys Res Commun. 1991 Jan 31;174(2):1028-34. doi: 10.1016/0006-291x(91)91522-e.
The Tetrahymena 14-nm filament-forming protein (49K protein) is a structural protein involved in oral morphogenesis and in pronuclear behavior during conjugation. Cloning the 49K protein gene from a Tetrahymena thermophila cDNA library, we found that its primary structure exhibits a high sequence identity (51.5%) with porcine heart citrate synthase and retains functional domains. The 49K protein actually possesses citrate synthase activity, and is detected in mitochondria. These results suggest that the 49K protein has dual functions as both a respiratory enzyme and a structural protein in the cytoskeleton.
嗜热四膜虫14纳米丝状形成蛋白（49K蛋白）是一种结构蛋白，参与口器形态发生以及接合过程中的原核行为。从嗜热四膜虫的cDNA文库中克隆49K蛋白基因时，我们发现其一级结构与猪心柠檬酸合酶具有高度的序列同一性（51.5%），并保留了功能结构域。49K蛋白实际上具有柠檬酸合酶活性，且在线粒体中被检测到。这些结果表明，49K蛋白在细胞骨架中兼具呼吸酶和结构蛋白的双重功能。
