A protein tyrosine phosphatase-like protein from baculovirus has RNA 5'-triphosphatase and diphosphatase activities.
A protein tyrosine phosphatase-like protein from baculovirus has RNA 5'-triphosphatase and diphosphatase activities.
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DOI：
10.1073/pnas.95.17.9808
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发表时间：
1998-08
影响因子：
11.1
通讯作者：
T. Takagi;G. Taylor;T. Kusakabe;H. Charbonneau;S. Buratowski
中科院分区：
文献类型：
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作者：
T. Takagi;G. Taylor;T. Kusakabe;H. Charbonneau;S. Buratowski
蛋白酪氨酸磷酸酶（PTP）的超家族包括至少一种具有RNA底物的酶。我们最近发现秀丽隐杆线虫mRNA加帽酶的RNA三磷酸酶结构域与PTP酶家族的序列相似性和机制有关。在序列上与加帽酶三磷酸酶最相似的PTP是BVP，一种由苜蓿银纹夜蛾核型多角体病毒编码的双特异性PTP。尽管BVP之前已被证明具有适度的酪氨酸和丝氨酸/苏氨酸磷酸酶活性，但我们发现它作为RNA 5 '-磷酸酶的活性要强得多。BVP顺序地从三磷酸终止的RNA的5'末端去除γ和β磷酸，留下5'-单磷酸末端。活性是特定的多核苷酸;核苷酸三磷酸不水解。活性位点半胱氨酸被丝氨酸取代的突变蛋白质是无活性的。其他三个双特异性PTP（VH 1，VHR和Cdc 14）没有表现出可检测的RNA磷酸酶活性。因此，加帽酶和BVP是不同的PTP样亚家族的成员，可以从RNA中去除磷酸盐。
The superfamily of protein tyrosine phosphatases (PTPs) includes at least one enzyme with an RNA substrate. We recently showed that the RNA triphosphatase domain of the Caenorhabditis elegans mRNA capping enzyme is related to the PTP enzyme family by sequence similarity and mechanism. The PTP most similar in sequence to the capping enzyme triphosphatase is BVP, a dual-specificity PTP encoded by the Autographa californica nuclear polyhedrosis virus. Although BVP previously has been shown to have modest tyrosine and serine/threonine phosphatase activity, we find that it is much more potent as an RNA 5'-phosphatase. BVP sequentially removes gamma and beta phosphates from the 5' end of triphosphate-terminated RNA, leaving a 5'-monophosphate end. The activity was specific for polynucleotides; nucleotide triphosphates were not hydrolyzed. A mutant protein in which the active site cysteine was replaced with serine was inactive. Three other dual-specificity PTPs (VH1, VHR, and Cdc14) did not exhibit detectable RNA phosphatase activity. Therefore, capping enzyme and BVP are members of a distinct PTP-like subfamily that can remove phosphates from RNA.