Schaller A, Schmid J, Leibinger U, Amrhein N
Institute of Plant Sciences, Federal Institute of Technology Zürich, Switzerland.
J Biol Chem. 1991 Nov 15;266(32):21434-8.
Chorismate synthase catalyzes the last common step in the biosynthesis of the three aromatic amino acids in microorganisms and plants. We have cloned a cDNA for this enzyme from the higher plant Corydalis sempervirens. This is the first chorismate synthase cDNA from a eukaryotic organism. The nucleotide sequence was determined and the identity of the cDNA was confirmed by the amino acid sequence of tryptic peptides obtained from purified chorismate synthase. The homology to the two known bacterial sequences is about 48%. The cDNA contains an open reading frame of 1341 base pairs, encoding a protein of 447 amino acids. This protein with a molecular mass of 48,100 daltons resembles a chorismate synthase precursor targeted for chloroplast import. Multiple sites of polyadenylation were observed in chorismate synthase mRNAs.
分支酸合酶催化微生物和植物中三种芳香族氨基酸生物合成的最后一个共同步骤。我们从高等植物延胡索中克隆了该酶的cDNA。这是来自真核生物的第一个分支酸合酶cDNA。测定了核苷酸序列,并通过从纯化的分支酸合酶获得的胰蛋白酶肽的氨基酸序列证实了该cDNA的身份。与两个已知细菌序列的同源性约为48%。该cDNA包含一个1341个碱基对的开放阅读框,编码一个447个氨基酸的蛋白质。这种分子量为48,100道尔顿的蛋白质类似于靶向叶绿体导入的分支酸合酶前体。在分支酸合酶mRNA中观察到多个聚腺苷酸化位点。