摘要
3-羟甲基戊二酰辅酶A-还原酶(3-hydroxy-3-methylglutaryl coenzyme A reductase,HMGR)是甲羟戊酸途径的关键酶。获得芫菁体内HMGR基因信息是确定甲羟戊酸途径与斑蝥素合成相关性的基础。本研究利用RACE技术从细纹豆芫菁Epicauta mannerheimi(Mklin)体内克隆获得HMGR基因全长cDNA序列,命名为EmHMGR(GenBank登录号为JQ690539)。该基因全长3118bp,其中5'端非翻译区178bp,3'端非翻译区414bp,开放阅读框2526bp,编码842个氨基酸。推测的蛋白质分子量为92.8kDa,理论等电点为6.0,预测分子式为C4135H6604N1098O1216S50,不稳定系数为43.37,总亲水性系数为0.091,为疏水性不稳定蛋白。序列分析发现该基因编码的蛋白与已报道的其他昆虫HMGR的氨基酸序列一致性达50%以上,而且包含HMGR_Class I保守功能域、固醇敏感多肽区及HMGR蛋白的其他保守功能位点。系统进化分析发现该基因与叶甲科昆虫HMGR基因的关系最近。本研究首次从芫菁科昆虫体内克隆获得甲羟戊酸途径的关键酶EmHMGR基因,为后期芫菁体内斑蝥素生物合成途径的研究奠定了基础。
3-Hydroxy-3-methylglutaryl coenzyme A reductase （HMGR） is a key enzyme of the mevalonate pathway. Obtaining HMGR gene information is the basis of studying the relationship between cantharidin biosynthesis and the mevalonate pathway. In this study, a full-length cDNA of the HMGR gene was cloned from the blister beetle Epicauta mannerheimi （M^iklin） by RACE technology, which was named EmHMGR （GeneBank accession no. JQ690539 ）. The full-length of EmHMGR is 3 118 bp with an ORF of 2 526 bp, containing a 5＇-untranslated region （5＇-UTR） of 178 bp and a 3＇UTR of 414 bp. It encodes a deduced protein of 842-amino acid residues, with a predicted molecular mass of 92.8 kDa and isoeletric point （pI） of 6.0. Its predicted molecular formula is C4135 H6604 N109s 01216 S50. Bioinformatical analysis showed that its instability index is 43.37 and the GRAVY 0.091, suggesting that EmHMGR is an unstable hydrophobic protein. The deduced protein EmHMGR has the conserved functional domain of HMGR_Class I and the sterol-sensing domain, and shares more than 50% amino acid identity with HMGRs from other insects. Phylogenetic analysis showed that EmHMGR has the closest relationship with HMGRs of chrysomelids. This study provides the basis for further research on the biosynthetic pathway of cantharidin in the blister beetles.
出处
《昆虫学报》
CAS
CSCD
北大核心
2012年第7期860-868,共9页
Acta Entomologica Sinica
基金
公益性行业(农业)科研专项(200903052)
中国博士后科学基金(20090451405)
