【摘要】 马铃薯Y病毒属病毒编码的辅助成分-蛋白酶(helper component-proteinase,HC-Pro)是第一个被鉴定的RNA沉默抑制因子。本研究通过定点突变的方法获得了马铃薯A病毒(Potato virus A,PVA)HC-Pro的3个突变体,利用农杆菌共浸润的方法分析了这些突变对HC-Pro抑制RNA沉默活性的影响。与野生型HC-Pro处理相比,Phe6、Asn11缺失突变体的处理中绿色荧光减弱,而Ile250-Gly251-Asn252(IGN)基序中的Ile和Gly分别突变为Asp和Glu的处理中观察不到绿色荧光。该结果表明Phe6、Asn11和IGN2503个位点均参与调控HC-Pro的抑制RNA沉默活性。更多还原

【Abstract】 The helper component-proteinase(HC-Pro) encoded by potyviruses is the first identified RNA silencing suppressor.In the study,three mutants of Potato virus A(PVA) HC-Pro were obtained via site-directed mutagenesis and analyzed for their activities on RNA silencing via agroinfiltration.Compared with that of wild type HC-Pro,the treatment with deletion mutants of amino acids Phe6 and Asn11 resulted in reduced green fluorescence,while treatment with substitution mutant of Ile250-Gly251-Asn252 motif to Asp250Glu251Asn252 resulted in no fluorescence.These results suggested that amino acids Phe6,Asn11 and motif Ile250-Gly251-Asn252 are involved in modulating the RNA silencing suppression activity of HC-Pro.更多还原