烟草β-1,3-葡聚糖酶的蛋白序列分析

Analysis of Protein Sequence of Beta-1,3-glucan Enzyme in Tobacco

葡聚糖酶是分布较为广泛且参与植物生理活动的一类蛋白,研究烟草葡聚糖酶蛋白序列,对掌握其作用机制具有重要的意义。分别采用NETPHOS,SMART,MEM,CLUSTAL和MEGA工具检测并分析烟草葡聚糖酶的磷酸化位点、蛋白结构、保守基序和进化树。结果表明,Nt BGl均含有丝氨酸、苏氨酸和酪氨酸的磷酸位点,其中Nt BGl-2磷酸位点最多(分别为25,8,4个);Nt BGl均含有信号肽和O-糖基水解酶结构域,能够参与多种碳水化合物代谢过程,具有水解酶活性和水解O-糖基化合物的功能;Nt BGl具有的核心保守基序区为Motif-1—Motif-2—Motif-7—Motif-5—Motif-3—Motif-4—Motif-6,Nt BGl-1和Nt BGl-2含有特异的Motif-8,Motif-9和Motif-10;烟草的葡聚糖酶与拟南芥聚为一类,且Nt BGl-1和Nt BGl-2属于亚组Ⅰ,Nt BGl-3属于亚组Ⅱ。

Dextranase was a type of protein that is widely distributed and involved in plant physiological activities, and the study of dextranase protein sequence was of great significance to master its thnctional mechanism. NETPHOS, SMART, MEM, CLUSTAL and MEGA tools were used to detect and analyze the phosphorylation sites, protein structures, conserved motifs and phylogenetic tree of tobacco glucanase. The resuhs showed that NtBG1 contained the phosphorylation site of serine, threonine and tyrosine, NtBG1-2 had the most phospholTlation site, and the above three phosphorylation sites were 25, 8, and 4, respectively. NtBG1 contained signal peptide and O- glycosyl hydrolase domain, and it could participate in many carbohydrate metabolisnl processes, and also had the tunction of hydrolase activity and hydrolysis of O- glycosyl compounds. The core area of a conserved motif in NtBG1 was Motif-1 - Motif-2 - Motif-7 - Motif-5 - Motif-3 - Motif-4 - Motif-6, NtBGI-1 and NtBGI-2 also contained specific Motif-8, Motif-9 and Motif-10. The glucanase of tobacco was clustered with Arabidopsis thaliana, which NtBGI-1 and NtBGI-2 belonged to subgroup I, NtBGI-3 belonged to subgroup II.