摘要
3-羟基-3-甲基戊二酸单酰辅酶A还原酶(HMGCR)是甲羟戊酸途径中的限速酶之一,其表达水平和催化活性会影响萜类及其衍生物的合成量.研究从红冬孢酵母YM25235菌株中克隆到一个HMGCR基因,命名为RkHMGCR.序列分析结果显示,RkHMGCR包含一个3981 bp的开放阅读框,编码1326个氨基酸,其编码的氨基酸序列与已报道的HMGCR同样具有保守的2个底物结合位点、2个NADP(H)结合位点和与催化活性相关的4个关键氨基酸残基,表明RkHMGCR是一个潜在的新的HMGCR基因.将RkHMGCR转回到YM25235菌株中进行过表达,分析结果显示,基因过表达使YM25235菌株中类胡萝卜素含量提高了42.21%,菌株中油脂和脂肪酸含量分别降低了28.93%和20.31%,这与部分类胡萝卜素合成和脂肪酸代谢相关基因的转录分析结果一致.研究结果可为进一步通过代谢工程手段提高产油红酵母中类胡萝卜素及其特定组分含量的研究提供参考.
3-hydroxy-3-methylglutaryl-CoA reductase(HMGCR)is one of the rate-limiting enzymes in the mevalonate pathway,whose expression level and catalytic activity affect the biosynthesis of terpenes and the derivatives.In this study,a HMGCR homologous gene RkHMGCR was cloned from Rhodosporidium kratochvilovae strain YM25235.Sequence analysis showed that RkHMGCR contains an open reading frame of 3981 bp,encoding a protein RkHMGCR of 1326 amino acids.Similar to the known HMGCRs,RkHMGCR contains conserved motifs including two conserved substrate-binding sites,two conserved NADP(H)-binding sites and four key amino acid residues involved with catalytic activity,indicating that the RkHMGCR is a potential new HMGCR gene.RkHMGCR was further transformed into YM25235 for over expression.Analysis results showed that the over-expression led to an increase of total carotenoids in the YM25235 by 42.21%,whereas the lipid and fatty acids content were decreased by 28.93%and 20.31%,respectively,which were consistent with the transcription analysis results of some genes involved in carotenoid biosynthesis and fatty acid metabolism.This study can provide references for further research on increasing the content of carotenoids and their specific components in oleaginous red yeast through metabolic engineering.
作者
和美霞
陈波
胡丽
张晓庆
季秀玲
魏云林
张琦
HE Mei-xia;CHEN Bo;HU Li;ZHANG Xiao-qing;JI Xiu-ling;WEI Yun-lin;ZHANG Qi(College of Life Science and Technology,Kunming University of Science and Technology,Kunming 650500,Yunnan,China)
出处
《云南大学学报（自然科学版）》
CAS
CSCD
北大核心
2021年第5期1018-1027,共10页
Journal of Yunnan University(Natural Sciences Edition)
基金
国家自然科学基金(31660454,31960466).
关键词
红冬孢酵母
RkHMGCR基因
过表达
类胡萝卜素
脂肪酸
Rhodosporidium kratochvilovae
3-hydroxy-3-methylglutaryl-CoA reductase gene
overexpression
carotenoids
fatty acids
