目的 从茯苓Poria cocos中克隆出细胞色素P450还原酶（CPR）基因，并对其进行生物信息学分析。方法 利用茯苓转录组注释信息，通过RACE扩增得到茯苓CPR基因（PcCPR）全长，并PCR得到对应基因组DNA序列。通过生物信息学方法，对该基因编码蛋白的特征进行分析，I-TASSER模拟出蛋白三级结构，MEGA构建蛋白系统进化树。结果 获得含有完整开放阅读框（ORF）的cDNA全长2 514 bp（GenBank号为KP768251），PcCPR的基因组DNA 5 292 bp（GenBank号为KP896487），含4个外显子、3个内含子。基因编码732个氨基酸的蛋白，相对分子质量81 147，等电点（pI）为5.39，为不稳定性亲水蛋白，非分泌蛋白，且不具有信号识别功能。蛋白定位于内质网上，第7～22位氨基酸为跨膜区；具有2个黄素结合的保守结构域，FAD、NADP的结合位点各自在蛋白三级结构空间上相邻近。同源性分析显示，PcCPR与担子菌CPR的相似性明显高于子囊菌CPR。结论 成功从茯苓中克隆得到PcCPR基因，为进一步研究PcCPR及相关代谢提供基础。

Objective To clone cytochrome P450 reductase (PcCPR) gene from Poria cocos and to characterize with bioinformatics methods. Methods According to annotated transcriptome of P. cocos, the PcCPR gene was cloned through RACE, and the genomic DNA sequence was further obtained through PCR. The characteristics of the encoded protein were analyzed using bioinformatics, the 3D structure of the protein was modeled with I-TASSER server, and phylogenetic tree of CPR was carried out with MEGA. Results The 2 514 bp full-length cDNA sequence (GenBank Accession No. KP768251) and the 5 292 bp genomic DNA sequence (GenBank Accession No. KP896487) of PcCPR was obtained, which contained four exons and three introns. PcCPR encoded a protein with 732 amino acids. The protein was predicted to be an unstable hydrophilic protein with calculated molecular weight of 81 147 and isoelectric point 5.39. PcCPR does not have a signal peptide but has a transmembrane segment (aa residues 7 to 22), and it is anchored to endoplasmic reticulum. There are two flavin binding domains and many predicted FAD and NADP binding sites, these sites are adjacent respectively at 3D structure level. The homologous analysis indicates that PcCPR has a higher similarity with CPR from basidiomycetes than CPR from ascomycetes. Conclusion The PcCPR was successfully cloned, which will provide a foundation for researches on PcCPR and PcCPR associated metabolic.

国家“十二五”科技支撑计划项目（2011BAI06B03）