节肢动物α-淀粉酶系统进化树构建及分析

Phylogenetic Tree Construction and Analysis of alpha-amylases in Arthropod

目的:构建节肢动物α-淀粉酶的系统进化树,探讨其进化关系,找出进化树中聚类在一起的α-淀粉酶的特异性序列。方法:在美国国立生物技术信息中心(National Center for Biotechnology Information,NCBI)数据库中选取了56个节肢动物的α-淀粉酶氨基酸序列,利用CLUSTALX2.0进行序列比对、MEGA6.0建立进化树,通过BOXSHADE找到聚类的α-淀粉酶特异性序列。结果:56个α-淀粉酶聚类成A、B、C、D四大簇,A簇特异性序列为"VD NHD NQ",B簇特异性序列为"ID NHD NX",C簇特异性序列为"ID NHD NQ",D簇特异性序列为"XGN NHD X"。A、B、C、D四簇都含有保守的NHD(天冬酰胺-组氨酸-天冬氨酸)序列,但序列两端氨基酸种类不同。结论:56个节肢动物α-淀粉酶分为4簇,每簇都有其特异性序列,但都含有保守序列NHD。

Objective：To investigate the evolutionary relationship of alpha-amylases among different arthropods by constructing phylogenetic tree and to find the specific sequences of the alpha-amylases in the phylogenetic tree.Methods：56 amino acid sequences encoding alpha-amylase of different species indexed in Arthropoda were downloaded from National Center for Biotechnology Information （NCBI）.CLUSTALX2.0 was used for sequence alignment,and MEGA6.0 was used to establish the phylogenetic tree.By using the BOXSHADE,the clusters of alpha-amylase specific sequence were explored.Results：The 56 amino acid sequences encoding alpha-amylases were grouped into four major clusters in phylogenetic tree,which were named as A,B,C,D.The specific sequence are VD （NHD）NQ for Cluster A,ID（NHD） NX Cluster B,are ID （NHD） NQ Cluster C,and XGN （NHD） X for Cluster D.The conserved sequences are NHD （Asn-His-Asp） for all of these amino acids sequences.Conclusion：The amino acid sequences encoding arthropod alpha-amylase were divided into four major clusters.Each cluster has its own special sequence.All the sequences have the conserved NHD.