PROTEOLYTIC MATURATION OF THE 206-KDA NONSTRUCTURAL PROTEIN ENCODED BY TURNIP YELLOW MOSAIC-VIRUS RNA
PROTEOLYTIC MATURATION OF THE 206-KDA NONSTRUCTURAL PROTEIN ENCODED BY TURNIP YELLOW MOSAIC-VIRUS RNA
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DOI：
10.1016/0042-6822(91)90851-2
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发表时间：
1991-09-01
期刊：
影响因子：
3.7
通讯作者：
DREHER, TW
中科院分区：
文献类型：
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作者：
BRANSOM, KL;WEILAND, JJ;DREHER, TW
芜菁黄花叶病毒基因组RNA （ORF-206）的最长开放阅读框编码一个206kda的非结构蛋白。ORF-206最突出的体外翻译产物是全长p206和一个更短的n -共端150-kDa蛋白。我们通过免疫沉淀的方法证实了ORF-206编码的n端和c端抗血清的体外翻译产物的这些定位。通过体外翻译从TYMV RNA的cDNA克隆pTYMC转录的缺失和替代衍生物，研究了ORF-206产生150 kda蛋白的机制。以下观察结果表明，150-kDa蛋白和c -末端70-kDa蛋白是由ORF-206通过自蛋白水解产生的：(1)ORF-206编码的两个区域对于150-kDa蛋白的形成是必需的：氨基酸555和1051之间的区域，假设编码蛋白酶，氨基酸1253和1261之间的区域，被认为构成蛋白酶识别和/或裂解位点。(2)氨基酸1253和1261之间发生替换的突变体在体外翻译中产生低水平的150 kda蛋白，也具有高水平的p206和低水平的70 kda蛋白。(3) 150-kDa蛋白的形成速率对稀释不敏感，表明蛋白水解主要是顺式发生的。
The longest open reading frame of turnip yellow mosaic virus genomic RNA (ORF-206) encodes a 206-kDa nonstructural protein. The most prominentin vitrotranslation products of ORF-206 are the full-length p206 and a shorter N-coterminal 150-kDa protein. We have confirmed these assignments by immunoprecipitation ofin vitrotranslation products with antisera raised to N-terminal and C-terminal regions encoded by ORF-206. The mechanism by which the 150-kDa protein arises from ORF-206 was investigated byin vitrotranslation of deletion and substitution derivatives transcribed from pTYMC, a cDNA clone of TYMV RNA. The following observations demonstrate that the 150-kDa protein and a C-terminal 70-kDa protein arise from ORF-206 by autoproteolysis: (1) Two regions encoded by ORF-206 were necessary for the formation of the 150-kDa protein: a domain between amino acids 555 and 1051, postulated to encode a protease, and the region between amino acids 1253 and 1261, thought to constitute the protease recognition and/or cleavage site. (2) Mutants with substitutions between amino acids 1253 and 1261 that produce low levels of the 150-kDa protein inin vitrotranslations also have high levels of p206 and low levels of the 70-kDa protein. (3) The rate of formation of the 150-kDa protein is dilution insensitive, suggesting that proteolysis occurs mainlyin cis.