ADENOVIRUS DNA-REPLICATION INVITRO - IDENTIFICATION OF A HOST FACTOR THAT STIMULATES SYNTHESIS OF THE PRE-TERMINAL PROTEIN-DCMP COMPLEX
ADENOVIRUS DNA-REPLICATION INVITRO - IDENTIFICATION OF A HOST FACTOR THAT STIMULATES SYNTHESIS OF THE PRE-TERMINAL PROTEIN-DCMP COMPLEX
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DOI：
10.1073/pnas.79.21.6438
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发表时间：
1982-01-01
期刊：
影响因子：
--
通讯作者：
HURWITZ, J
中科院分区：
文献类型：
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作者：
NAGATA, K;GUGGENHEIMER, RA;HURWITZ, J
已经分离并表征了参与腺病毒（Ad）末端蛋白（pTP）的80，000-道尔顿前体与5“-dCMP之间共价复合物形成的蛋白因子。这种47，000-道尔顿的蛋白质从未感染的人宫颈癌HeLa细胞的核提取物中分离出来，被命名为核因子I。它不含可检测的DNA聚合酶α，β。和γ活动在Ad DNA-prot、Ad蛋白组分（含有pTP和Ad相关的DNA聚合酶）、ATP、Mg 2+和dCTP、核因子I的存在下，刺激pTP-dCMP复合物的形成。加入Ad DNA结合蛋白（Ad DBP）使pTP-dCMP复合物的形成完全依赖于核因子I的加入。当Ad DNA-prot被vphiX 174单链环状DNA取代时，pTP-dCMP复合物的形成仅需要Ad-蛋白部分; Ad DBP和ATP是抑制性的，并且核因子I对该反应没有影响。显然，在不存在Ad DBP的情况下用Ad DNA-prot观察到的起始反应发生在单链DNA位点。在Ad DBP存在下，这些位点被阻断，从而在pTP-dCMP复合物形成中产生对核因子I的需要。
A protein factor that participates in the formation of a covalent complex between the 80,000-dalton precursor of the adenovirus (Ad) terminal protein (pTP) and 5''-dCMP has been isolated and characterized. This 47,000-dalton protein, isolated from nuclear extracts of uninfected human cervical carcinoma HeLa cells, was designated nuclear factor I. It is free of detectable DNA polymerase .alpha., .beta. and .gamma. activities. In the presence of Ad DNA-prot, the Ad-protein fraction (containing the pTP and the Ad-associated DNA polymerase), ATP, Mg2+ and dCTP, nuclear factor I stimulates formation of the pTP-dCMP complex. Addition of the Ad DNA binding protein (Ad DBP) renders the formation of the pTP-dCMP complex completely dependent on the addition of nuclear factor I. When Ad DNA-prot is replaced with .vphi.X174 single-stranded circular DNA, pTP-dCMP complex formation requires only the Ad-protein fraction; Ad DBP and ATP are inhibitory and nuclear factor I has no effect on this reaction. Evidently, the initiation reaction observed with Ad DNA-prot in the absence of Ad DBP occurs at single-stranded DNA sites. In the presence of Ad DBP, these sites are blocked thus creating a requirement for nuclear factor I in pTP-dCMP complex formation.