以结球甘蓝(Brassica oleracea L.Var.capitataL.)E1花粉为试材,对萌发前后的花粉总蛋白进行双向电泳及差异蛋白质谱分析,发现延伸因子BoEF-Tu蛋白在花粉萌发后较萌发前表达上调。利用同源克隆得到甘蓝BoEF-Tu基因的全长cDNA序列,其长度为l728bp,具有一个完整开放阅读框(ORF),位于112—1473bp处,编码453个氨基酸残基,预测分子量为49.17kD,等电点为6.52。生物信息学分析表明:BoEF-Tu蛋白含有9个α-螺旋结构,18个β-折叠结构,不含信号肽和跨膜区,在106~121位氨基酸残基处有1个GTP结合区域(DKAPEEEKKRGITIATA)。氨基酸同源性分析表明,BoEF-Tu与拟南芥EF-TuM同源性较高,达到93%;系统进化分析表明,BoEF-Tu与拟南芥EF-Tu的亲缘关系最近。
The elongation factor BoEF-Tu was isolated and characterized from cabbage (Brassica oleracea L. var. capitata L. ) line E1 using RT-PCR and RACE-PCR after two-dimensional electrophoresis of cabbage pollen total proteins, which found that BoEF-Tu protein was upregulated when pollens were germinated. The cabbage BoEF-Tu eDNA clone contained 1 728 bp with an open reading frame (ORF) located from 112 to 1 473 bp, encoding a protein of 453 amino acids. The predicted molecular mass of BoEF-Tu was 49.17 kD with acidic pI of 6.52. Bioinformatic analysis results showed that BoEF-Tu protein might contain 9 a-helixes and 18 13-folds, and a GTP-binding signature (DKAPEEKKRGITIATA) was located from 106 to 121 amino acid residues, but had no signal peptide sequences and transmembraneregion. Homology analysis of the deduced amino acids indicated that the sequences had 93% similarity with Arabidopsis thaliana EF-TuM. The phylogenetic tree showed that the BoEF-Tu had the closest genetic relationship with Arabidopsis thaliana EF-Tu.