ENZYMATIC-ACTIVITY IN UNINFECTED CELLS THAT CLEAVES THE LINKAGE BETWEEN POLIO-VIRION RNA AND THE 5' TERMINAL PROTEIN
ENZYMATIC-ACTIVITY IN UNINFECTED CELLS THAT CLEAVES THE LINKAGE BETWEEN POLIO-VIRION RNA AND THE 5' TERMINAL PROTEIN
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DOI：
10.1016/0092-8674(78)90067-3
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发表时间：
1978-01-01
期刊：
影响因子：
64.5
通讯作者：
BALTIMORE, D
中科院分区：
文献类型：
--
作者：
AMBROS, V;PETTERSSON, RF;BALTIMORE, D
脊髓灰质炎病毒RNA上的5“末端蛋白（VPg）可以通过各种未感染细胞的无细胞提取物去除。这种可溶性酶活性在[人宫颈癌] HeLa细胞的细胞核和细胞质提取物中发现，并被Mg 2+激活。这种酶的活性切断连接蛋白质和RNA的酪氨酸-磷酸键。在部分纯化的形式中，它没有足够的非特异性蛋白酶或核酸酶活性来解释其作用。这种酶的存在意味着脊髓灰质炎病毒RNA在无细胞提取物中以缺乏5“末端蛋白的形式翻译。这种酶在未感染细胞中的作用尚不清楚。
The 5'' terminal protein (VPg) on poliovirion RNA can be removed by cell-free extracts from a variety of uninfected cells. This soluble enzymatic activity is found in both nuclear and cytoplasmic extracts of [human cervical carcinoma] HeLa cells and is activated by Mg2+. The enzyme activity cleaves the tyrosine-phosphate bond that links the protein to the RNA. In a partially purifed form it has insufficient nonspecific protease or nuclease activity to account for its action. The existence of this enzyme implies that poliovirus RNA is translated in cell-free extracts in a form that lacks the 5'' terminal protein. The role of this enzyme in the uninfected cell is not known.