Proteolytic processing of poliovirus polyprotein: elimination of 2Apro-mediated, alternative cleavage of polypeptide 3CD by in vitro mutagenesis.
Proteolytic processing of poliovirus polyprotein: elimination of 2Apro-mediated, alternative cleavage of polypeptide 3CD by in vitro mutagenesis.
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脊髓灰质炎病毒多蛋白的蛋白水解加工：通过体外诱变消除 2Apro 介导的多肽 3CD 的选择性裂解。
DOI：
10.1016/0042-6822(88)90511-9
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发表时间：
1988
期刊：
影响因子：
3.7
通讯作者：
Wimmer,E
中科院分区：
文献类型：
--
作者：
Lee,CK;Wimmer,E
许多脊髓灰质炎病毒株的多肽 3CD 可以在两个不同的氨基酸对处被切割。病毒蛋白酶3C和病毒聚合酶3D是由蛋白酶3C在Gln-Gly对上裂解产生的，而蛋白酶2A在Tyr-Gly对上裂解产生替代产物3C'和3D'。通过寡核苷酸定向诱变，将特定突变引入 1 型脊髓灰质炎病毒 (Mahoney) 感染性 cDNA 克隆的 3C'/3D'/ 裂解位点，以研究 3C' 和 3D' 在病毒增殖中的作用，并获得有关 2Apro 裂解特异性的信息。在该裂解位点的 -2 (P2) 位置用丙氨酸残基取代苏氨酸残基废除了裂解，而在裂解位点的氨基酸位置-1 (P1)处用苯丙氨酸残基取代酪氨酸残基并不影响加工。两个突变的 cDNA 克隆在转染时均产生感染性病毒（T1 47A 和 Y1 48F）。突变病毒的表型与亲本毒株相似。我们得出的结论是（i）3C'和3D'对于病毒复制不是必需的，（ii）裂解位点的Phe-Gly对可以被2Apro裂解，（iii）裂解位点P2位置的苏氨酸残基可能对2Apro的底物识别很重要。
The polypeptide 3CD of many poliovirus strains can be cleaved at two different amino acid pairs. The viral proteinase 3C and the viral polymerase 3D result from cleavage at a Gln-Gly pair by proteinase 3C, whereas cleavage at a Tyr-Gly pair by proteinase 2A yields the alternative products 3C′ and 3D′. Specific mutations were introduced into the 3C′/3D′/ cleavage site in an infectious cDNA clone of poliovirus type 1 (Mahoney) by oligonucleotide-directed mutagenesis in order to investigate the role of 3C′ and 3D′ in viral proliferation and to obtain information about the cleavage specificity of 2AproSubstitution of a threonine residue by an alanine residue at position -2 (P2) of this cleavage site abolished cleavage, whereas substitution of a tyrosine residue by a phenylalanine residue at amino acid position -1 (P1) of the cleavage site did not influence processing. Both mutated cDNA clones produced infectious viruses (T1 47A and Y1 48F) on transfection. The phenotypes of the mutant viruses were similar to that of the parental strain. We conclude that (i) 3C′ and 3D′ are not essential for virus replication, (ii) a Phe-Gly pair at the cleavage site can be cleaved by 2Apro, and (iii) a threonine residue in theP2position of the cleavage site may be important in substrate recognition by 2Apro.