摘要: |
采用同源克隆的方法和RACE 技术, 从坛紫菜cDNA 中获得了磷酸烯醇式丙酮酸羧化酶(PEPC)的序列, 该段序列含2538 个核苷酸包含一个终止密码子TAG 和191 bp 的3′端非编码区(UTR), 可编码846 个氨基酸。该段序列中无跨膜结构和信号肽序列, 推导的氨基酸序列中 C 末端第813 位氨基酸是丙氨酸(A), 表明是一个C3型基因。相似性分析表明, 坛紫菜PEPC 与其他物种有很高的一致性, 约为35%~50%。结构分析显示, 该序列具有两个PEPC 基因保守活性位点和5 种模式的其他功能位点。进化分析显示, 坛紫菜PEPC 羧化酶氨基酸序列更接近于C3型, 进化上更为古老。该实验对进一步深入研究坛紫菜PEPC 羧化酶功能及坛紫菜光合作用、碳代谢等具有重要的参考价值。 |
关键词: 坛紫菜 PEPC 基因 序列分析 系统进化分析 |
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基金项目:国家自然科学基金重点项目(30830015); 海洋公益性行业科研专项项目(201105008-2, 201105023-7) |
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Cloning and analysis of the phosphoenolpyruvate carboxylase gene of Porphyra haitanensis (Rhodophyta) |
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Abstract: |
Phosphoenolpyruvate carboxylase (PEPC; EC 4.1.1.31) plays an important role in photosynthesis. To get a deeper insight into the PEPC gene of Porphyra haitanensis T. J. Chang et B. F. Zheng (Bangiales, Rhodophyta), we cloned a partial-length cDNA by homology cloning and RACE. This sequence includes 2538bp encoding a propetide of 846 amino acid residues. The deduced polypeptide shows high identities with the PEPC genes ranging from bacteria and unicellular algae to green plant. Phylogenetic tree analysis shows that he PEPC gene from the Porphyra haitanensis is a C3-like PEPC and more closely related to the ancestral type. |
Key words: Porphyra haitanensis phosphoenolpyruvate carboxylase gene sequence analysis phylogenetic tree analysis |