Fischer H, Haake V, Horstmann C, Jensen U
Universität Bayreuth, Lehrstuhl Pflanzenökologie und Systematik, Germany.
Eur J Biochem. 1995 May 1;229(3):645-50. doi: 10.1111/j.1432-1033.1995.tb20509.x.
We have cloned and sequenced three different cDNAs encoding legumins of Magnolia salicifolia. Analysis of the nucleotide and derived amino acid sequences shows that the cDNAs designated A2, A11, and B14 represent two divergent subfamilies with nucleotide similarities of only about 55%. The B14 cDNA codes for a relatively methionine-rich legumin precursor, and the beta-chain of this protein is shown to be glycosylated; neither feature is common in legumin. In an evolutionary analysis, the B14 legumin cDNA is relatively similar to gymnospermous legumin sequences and paralogous to all angiosperm legumins hitherto known. The A legumin sequence clusters with those of monocot legumins in a low angiosperm branch. We conclude that the evolution of legumin genes in angiosperms involved an early gene duplication which resulted in the progenitor of the B14 legumin, on the one hand, and the progenitor of A2, A11 and modern angiosperm legumins, on the other hand.
我们已经克隆并测序了三种不同的编码柳叶木兰豆球蛋白的cDNA。对核苷酸和推导的氨基酸序列的分析表明，命名为A2、A11和B14的cDNA代表两个不同的亚家族，其核苷酸相似性仅约为55%。B14 cDNA编码一种相对富含甲硫氨酸的豆球蛋白前体，并且该蛋白的β链被证明是糖基化的；这两个特征在豆球蛋白中都不常见。在进化分析中，B14豆球蛋白cDNA与裸子植物豆球蛋白序列相对相似，并且与迄今已知的所有被子植物豆球蛋白是旁系同源的。A豆球蛋白序列在低等被子植物分支中与单子叶植物豆球蛋白的序列聚类。我们得出结论，被子植物中豆球蛋白基因的进化涉及早期的基因复制，一方面产生了B14豆球蛋白的祖先，另一方面产生了A2、A11和现代被子植物豆球蛋白的祖先。
