Luo Hong-Mei, Song Jing-Yuan, Li Xue-Ying, Sun Chao, Li Chun-Fang, Luo Xiang, Li Ying, Chen Shi-Lin
National Engineering Laboratory for Breeding of Endangered Medicinal Materials, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100193, China.
Yao Xue Xue Bao. 2013 Feb;48(2):219-27.
3-Hydroxy-3-methylglutaryl coenzyme-A reductase (HMGR), the first enzyme of mavalonic acid pathway, is one of the key devices involved in ginsenoside biosynthesis based on synthetic biology approach. The open reading frame of a novel HMGR gene from Panax ginseng (PgHMGR2) was cloned and analyzed in this study. PgHMGR2-encoding protein showed 71.6% sequence similarity to a P. ginseng HMGR in GenBank. The full-length cDNA sequence of PgHMGR2 containing 1 770 bp, which encodes 589 amino acids, was cloned by RT-PCR strategy from P. ginseng. The bioinformatic analysis showed that PgHMGR2-encoding protein contained two transmembrane regions and the HMG_CoA_reductase domain, without signal peptide. The protein sequence of PgHMGR2 had the highest sequence similarity (99%) with Panax quinquefolius HMGR (GenBank accession No. ACV65036). The expression level of PgHMGR2 was the highest in flower based on a real-time PCR analysis, followed by leaf and root, and the lowest was in stem. The result will provide a foundation for exploring the molecular function of PgHMGR2 involved in ginsenoside biosynthesis based on synthetic biology approach in P. ginseng plants.
3-羟基-3-甲基戊二酰辅酶A还原酶（HMGR）是甲羟戊酸途径的首个酶，是基于合成生物学方法参与人参皂苷生物合成的关键元件之一。本研究克隆并分析了来自人参（PgHMGR2）的一个新HMGR基因的开放阅读框。编码PgHMGR2的蛋白质与GenBank中人参的一种HMGR的序列相似性为71.6%。通过RT-PCR策略从人参中克隆了包含1770 bp的PgHMGR2全长cDNA序列，其编码589个氨基酸。生物信息学分析表明编码PgHMGR2的蛋白质含有两个跨膜区域和HMG_CoA_还原酶结构域，无信号肽。PgHMGR2的蛋白质序列与人参三七HMGR（GenBank登录号ACV65036）的序列相似性最高（99%）。基于实时PCR分析，PgHMGR2在花中的表达水平最高，其次是叶和根，在茎中最低。该结果将为基于合成生物学方法探索PgHMGR2在人参植株人参皂苷生物合成中的分子功能奠定基础。
