摘要
【目的】预测并分析大丽轮枝菌基因组范围内的分泌蛋白,为大丽轮枝菌分泌蛋白致病机理的研究奠定基础。【方法】利用已公布的大丽轮枝菌全基因组序列,组合使用生物信息学软件SignalP、TargetP、TMHMM、Big-pi和PROSITE,预测大丽轮枝菌基因组范围内所有分泌蛋白,定义为分泌组。统计分析分泌组中蛋白N-端信号肽特点;应用碳水化合物活性酶类数据库和病原菌-寄主互作蛋白数据库对分泌组蛋白进行注释,预测分泌组中潜在果胶酶、纤维素酶和病原菌寄主互作蛋白;利用真菌激发子的保守结构域,预测分泌组中潜在的激发子蛋白集;应用BLASTP程序比较分析大丽轮枝菌和黑白轮枝菌分泌组,获得大丽轮枝菌相对于黑白轮枝菌特异的分泌蛋白。【结果】大丽轮枝菌分泌组共有922个蛋白。信号肽分析表明,以19个氨基酸为信号肽的蛋白数目最多,非极性氨基酸丙氨酸的出现频率最高,而有带电侧链的氨基酸天冬氨酸和谷氨酸的出现频率最低,信号肽的-3和-1位置上的氨基酸相对保守。大丽轮枝菌分泌组含有158个潜在的碳水化合物活性酶类,其中,包括10个果胶水解酶和14个果胶裂解酶;190个潜在的病原菌-寄主互作蛋白、97个含有RxLx[EDQ]模体的蛋白和52个富含半胱氨酸的小分子量分泌蛋白;58个相对于黑白轮枝菌分泌组特异的蛋白。【结论】本文建立了预测大丽轮枝菌分泌组蛋白的方法。分泌组蛋白信号肽长度具有高度的变异性,氨基酸组成多为脂肪族氨基酸,序列在C-端结构域较为保守。分泌组中包含大量潜在的果胶降解酶、病原菌-寄主互作蛋白、RxLx[EDQ]模体蛋白和富含半胱氨酸的小分子量蛋白等致病相关蛋白。
[Objective] The aim of this study was to predict and analyze secretome of Verticillium dahliae, an important soil-born fungal pathogen that causes vascular wilt diseases. [Method] The soflwares SignalP, TargetP, TMHMM, Big-pi and PROSITE were used to predict the sectetome of V. dahliae. Protein databases were used for secretome annotation to find putative pectinase, cellulose and pathogen-host interaction proteins. The proteins with common fungal effector character were investigated by a set of computer algorithms. By using BLASTP, the secretome of V.. dahliae and V. albo-atrum was compared to find V. dahliae specifically secreted proteins. [Result] A total of 922 possible secreted proteins were identified in E dahliae scretome. The most frequent amino acid in signal peptides is alanine, and the least is glutamic acid and aspartic acid. The amino acid in the position -3 and -1 are very conserved. The secretome is equipped with 158 carbohydrate-active enzymes which include 10 pectic hydrolases and 14 pectic lyases, 190 putative pathogen-host interaction proteins, 97 RxLx[EDQ] motif containing proteins and 52 small cysteine-rich secreted proteins, and 58 V. dahliae specifically secreted proteins compared with V. albo-atrum. [Conclusion] This study has provided secretome prediction algorithms for E dahliae. Length of signal peptides vary greatly. Composition of signal peptides are mainly aliphatic amino acid and sequences of signal peptides near C-terminal are conservative. V. dahliae secretome are rich in potential pectinase, pathogen-host interaction protein, RxLx[EDQ] motif containing protein and small cysteine-rich protein which may play roles in V. dahliae pathogenetic mechanism.
出处
《中国农业科学》
CAS
CSCD
北大核心
2011年第15期3142-3153,共12页
Scientia Agricultura Sinica
基金
国家"973"计划项目(2011CB100700)
国家科技基础性工作专项(SB2007FY027)
关键词
大丽轮枝菌
分泌蛋白
信号肽
碳水化合物活性酶
激发子
Verticillium dahliae
secreted protein
signal peptide
carbohydrate-active enzyme
effector
