新疆雪莲rbcs基因的克隆及序列分析

为获得新疆雪莲Rubisco（1,5-二磷酸核酮糖羧化酶/加氧酶）小亚基基因，并对其序列进行生物信息学分析；从已建立的新疆雪莲cDNA文库中，随机挑取单克隆，采用通用引物M13扩增并测序，测序结果在NCBI网址进行Blast比对，结果发现了2个与rbcs基因同源的序列并命名为sikrbcs1和sikrbcs2；生物信息学分析表明：sikrbcs1基因包含l个540 bp的完整开放阅读框，编码179个氨基酸，sikrbcs2基因包含l个420 bp的完整开放阅读框，编码139个氨基酸。sikrbcs1基因编码的蛋白质的理论等电点是8.90，分子量为20.1042 kD，具有2个跨膜区域，sikrbcs2基因编码的蛋白质理论等电点是7.58，分子量为15.1093 kD，不具有跨膜区域。氨基酸多序列比对表明，Sikrbcs1与黄顶菊和向日葵的相似性最高，达到83.89%，Sikrbcs2与向日葵的相似性最高达到57.54%；系统进化树显示表明，sikrbcs1和sikrbcs2都与菊花亲缘关系最近。

Cloning and Sequence Analysis of rbcs Gene from Sasussured involucrata Kar. et Kir

To obtain Rubisco (Ribulose-1,5-bisphosphate carboxylase/oxygenase) small subunit gene from Sasussured involucrata Kar.et Kir, in this study the gene was cloned and analyzed;Seeking monoclone in established cDNA library randomly for PCR directed with universal M13 primer and sequencing , comparing the sequence in NCBI ,finally we obtained the two rbcs gene homologous sequences ，named Sikrbcs1 and Sikrbcs2. Bioinformatics analysis indicated that the Sikrbcs1 cDNA contained an open reading frame of 540 nucleotides encoding 179 amino acids ,the Sikrbcs2 cDNA contained an open reading frame of 420 nucleotides encoding 139 amino acids. Forecasted the Sikrbcs1 protein relative molecular weight was 20.1042 kD, theoretical PI was 8.9, contained two span membrane structures, the Sikrbcs2 protein relative molecular weight was 15.1093 kD, theoretical PI was7.58, no span membrane structure. Multiple sequence alignment of rbcs proteins revealed that the amino acid sequence of Sikrbcs1 protein showed high identity of 83.89% to those of rbcs from Flaveriapringlei and Helianthusannuus, Sikrbcs2 showed high identity of 57.54% to that of rbcs from Helianthusannuus. Phylogenetic analysis further showed that the Sikrbcs1 and Sikrbcs2 had nearest relationship with Chrysanthemum xmorifolium.