GH78家族真菌α-L-鼠李糖苷酶分子系统进化关系分析

Analysis of Evolutionary Relationship of GH78 Fungal α-L-Rhamnosidase

摘要:

为了分析糖苷水解酶第78家族(glucoside hydrolase family 78，GH78)中真菌α-L-鼠李糖苷酶保守区及进化关系，本研究应用ClustalW2软件对87条GH78家族真菌α-L-鼠李糖苷酶进行多重序列比对，利用Block Maker进一步分析，得到了该家族真菌的共有完全氨基酸保守位点及保守区；利用SignalP 4.1 Server对序列进行信号肽预测；应用MEGA 6.0软件对ClustalW2结果进行遗传距离分析并构建分子系统进化树。GH78家族真菌87条序列虽然长度不等，但均包含AHGWSTGPTY、VTLDTGQNVAG和NELSIPTDGAKRD 3个保守区及多个完全保守氨基酸位点；87条序列中29条含有信号肽；属间遗传距离为0.7~48.5，种间遗传距离为0.4~48.5；分子系统进化树并不是依靠菌株来源进行聚类，而是依据是否为胞外酶进行聚类。该研究分析了GH78家族真菌α-L-鼠李糖苷酶的保守区及进化关系，为α-L-鼠李糖苷酶的工程改造奠定了基础。

Abstract:

In order to analyze the conserved regions and the evolutionary relationship of fungal α-L-rhamnosidase in glucoside hydrolase family 78 (GH78), 87 sequences of GH78 fungal α-L-rhamnosidases were collected and compared by ClustalW2 software. In addition, the conserved amino acid sites and the common conserved regions of GH78 fungal α-L-rhamnosidases were obtained by Block Maker. Meanwhile, the signal peptide was predicted by SignalP 4.1 Server. Besides, the genetic distance and the phylogenetic tree of 87 sequences were constructed by MEGA6.0 software. Although the amino acid sequences of fungal α-L-rhamnosidases had various lengths, all contained three conserved regions, including AHGWSTGPTY, VTLDTGQNVAG and NELSIPTDGAKRD, as well as a number of conserved amino acid sites. Moreover, 29 sequences contained signal peptides. The genetic distance between the genera was from 0.7 to 48.5, and the genetic distance of interspecies was from 0.4 to 48.5. Interestingly, it was found that the phylogenetic tree of the phylogenetic system was not clustered by the source of the strain, but on whether the extracellular enzyme was clustered. In this study, the conserved region and evolutionary relationships of GH78 α-L-rhamnosidases were analyzed, which laid the foundation for engineering modification of α-L-rhamnosidase.