Sjödahl S, Rödin J, Rask L
Department of Cell Research, Swedish University of Agricultural Sciences, Uppsala.
Eur J Biochem. 1991 Mar 28;196(3):617-21. doi: 10.1111/j.1432-1033.1991.tb15857.x.
Cruciferin (12S globulin) is the major seed protein in Brassica napus (oil seed rape). It is synthesized during seed development and consists of six subunit pairs. Each of these pairs is synthesized as a precursor containing one alpha and one beta chain. At least three different precursors exist (P1-3), giving rise to four different mature subunits (cru1-4). Several cruciferin clones were isolated from a seed mRNA cDNA library. Comparison of the deduced amino acid sequences of these clones to amino acid sequences of purified cruciferin chains and peptides identified them as coding for cru2/3 and cru4 subunits. From the amino acid sequences deduced from two overlapping cDNA clones, the precursor of the cru4 subunit was shown to consist of 465 amino acid residues. Comparison of cruciferin and cruciferin-related sequences from B. napus and Arabidopsis thaliana, respectively, suggested that early during evolution the Brassicaceae family only possessed two types of 11-12S globulin genes, like the present-day Fabaceae.
十字花科蛋白（12S球蛋白）是甘蓝型油菜（油菜籽）中的主要种子蛋白。它在种子发育过程中合成，由六个亚基对组成。这些亚基对中的每一个都是作为包含一条α链和一条β链的前体合成的。至少存在三种不同的前体（P1 - 3），产生四种不同的成熟亚基（cru1 - 4）。从种子mRNA cDNA文库中分离出了几个十字花科蛋白克隆。将这些克隆推导的氨基酸序列与纯化的十字花科蛋白链和肽的氨基酸序列进行比较，确定它们编码cru2/3和cru4亚基。从两个重叠的cDNA克隆推导的氨基酸序列来看，cru4亚基的前体由465个氨基酸残基组成。分别比较甘蓝型油菜和拟南芥的十字花科蛋白及十字花科蛋白相关序列表明，在进化早期十字花科家族仅拥有两种类型的11 - 12S球蛋白基因，就像当今的豆科植物一样。
