红花檵木两个查尔酮合成酶的克隆及生物信息学分析

Cloning and Bioinformatic Analysis of Two Chalcone Synthases from Loropetalum Chinense var.Rubrum

为了研究红花檵木花青苷生物合成的分子机制,克隆了红花檵木两个查尔酮合成酶LcCHSs基因,并对克隆的两个基因进行了生物信息学分析。利用RT-PCR技术,克隆得到红花檵木LcCHS1和LcCHS2基因,其中LcCHS1的开放阅读框(ORF)为1170 bp,编码389个氨基酸,LcCHS2的ORF为1182 bp,编码393个氨基酸。两个LcCHSs的氨基酸序列与来源于茶树(Camellia sinensis)、葡萄(Vitis vinifera)、拟南芥(Arabidopsis thaliana)、烟草(Nicotiana tabacum)等植物CHSs的氨基酸序列一致性超过83%,且两个LcCHSs的氨基酸序列中参与CHS酶类催化的3个残基(Cys164、His303和Asn336)和两段CHS酶类重要序列(“RLMMYQQGCFAGGTVLR”和“GVLFGFGPGL”)均严格保守,表明CHS在进化功能上的保守性。三级结构预测表明两个LcCHSs都能形成同源二聚体,且两个LcCHSs蛋白的空间结构非常相似。

In view of an investigation of the molecular mechanism of anthocyanin biosynthesis from Loropetalum chinense var.rubrum,a bioinformatical analysis has been made of the two chalcone synthase genes LcCHSs cloned from Loropetalum L.chinense var.rubrum.By adopting RT-PCR method,LcCHS1 and LcCHS2 genes of Loropetalum chinense var.rubrum have been cloned,with 1170 BP the open reading frame(ORF)of LcCHS1,encoding 389 amino acids,and with 1182 BP the ORF of LcCHS2,encoding 393 amino acids.The amino acid sequences identity of two LcCHSs are above 83%to other plant CHSs,such as Camellia sinensis,Vitis vinifera,Arabidopsis thaliana,Nicotiana tabacum.The catalytic triad(Cys164,His303 and Asn336)and two important sequences of CHS enzyme,“RLMMYQ QGCFAGGTVLR”and“GVLFGFGPGL”,are highly conserved,indicating a functional conservation of CHS during evolution.Tertiary structure prediction shows that both LcCHSs can form homodimers,with the spatial structures of the two LcCHSs proteins being very similar.