短柄五加(Acanthopanax brachypus)rbcL基因的结构分析

克隆了含完整短柄五加rbcL基因的3.2kb EcoRI片段,测定了该基因的核苷酸序列.所测核苷酸序列总长度为1924bp,其中编码区1428bp,编码475个氨基酸的蛋白质.测定的基因5’上游区共278bp,包含原核性质-35区(TTGCGC),-10区(TACAAT)及类似真核的TATA box元件(TATATA).5’前导区长194bp,其中SD序列为GGAGG,紧邻起始密码子上游.测定的3’下游区共218bp,含2个相邻的转录后可形成茎环结构的反向重复序列.短柄五加rbcL基因编码区推导的氨基酸序列与烟草、菠菜、豌豆、苜蓿、玉米、水稻、松树、地钱、衣藻和Anacystis的同源性分别为93.5％、94.11％、94.53％、94.74％、89.68％、92.21％、92.21％、92.63％、87.58％和80.84％.本文还对不同植物rbcL基因的启动区及部分5’和3’非编码区进行了比较分析.

Structural Analysis of rbcL Gene from an Endangered Plant Acanthopanax brachypus

A 3. 2kb EcoRI DNA fragment containing the complete chloroplast rbcL gene from Acanthopanax brachypus has been cloned. In addition to the 1428bp coding region encoding 475 amino acids of the gene, we sequenced 278bp upstream and 218bp downstream of the coding region. Possible ctpl and ctp2, equivalent to prokaryotic-35 and-10 elements, are TTGCGC and TACAAT, respectively. The 5' untranslated leader region is 194bp, the putative ribosome binding site in this region is GGAGG, located immediately upstream of the start codon. The 3' untranslated region contains two inverted repeat sequences, which in the mRNA may form stem-loop structures. The homology of rbcL amino acid sequence between A. brachypus and tobacco, spinach, pea, alfalfa, maize, rice, pine, Marchantia, Chlamydomonas and Anacystis are 93. 05%, 94. 11%, 94. 53%, 94.74%, 89.68%, 92. 21%, 92. 21%, 92. 63%, 87. 58% and 80. 84%, respectively. The promoter regions and part of the 5', 3' non-coding regions of rbcL from various plants were compared.