豌豆核糖体小亚基蛋白S21的cDNA克隆、序列分析及在G2豌豆中的表达研究

以G2豌豆幼苗为材料,构建了滴度为6.5×106pfu的cDNA文库,用同源序列筛选法从该文库中得到一个全长465bp的cDNA。杂交分析认为它是一完整的cDNA序列。DNA序列分析表明,它拥有一个282bp的开放读码框,编码94个氨基酸。计算机同源序列比较发现,它可能编码豌豆核糖体小亚基蛋白S21(RS21-PEA),因为该序列与已知的玉米、水稻S21在氨基酸全序列水平上有32%～35%的同源性,并含有与RNA结合的特征结构域。进化树分析显示S21蛋白可在一定程度上反映生物的进化及遗传变异趋势。

Cloning,Sequence and Analysis of a Pea cDNA Encoding the Ribosomal Protein S21

A 6 5×10 6pfu cDNA library was constructed from G2 pea leaf tissue.Using a synthetic oligomer deduced from previously reported maize and rice S21 nucleotide sequence as a probe,a 465 bp cDNA was identified.The result of Northern blot showed that it was well expressed in G2 pea.Sequencing and analyzing of the cDNA showed that it contained 78 bp and 105 bp in 5′ and 3′untranslated regions respectively,and 282 bp as the open reading frame.Its deduced amino acid sequence corresponded to a small ribosomal protein S21.Both conserved regions as well as ribosomal specific regions from the G2 pea S21 protein shared substantial sequence identity with other known S21 proteins.Further multiple sequence alignment showed that RS21 appeared to be well conserved among all eukaryotes.The phylogenetic tree drawn by ClustalW and Phylip software indicated that the relationship of S21 from different species corresponded to the evolutionary trend of ribosomal.