Quantification of the DNA cleavage and packaging proteins UL15 and UL28 in A and B capsids of herpes simplex virus type 1
Quantification of the DNA cleavage and packaging proteins UL15 and UL28 in A and B capsids of herpes simplex virus type 1
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DOI：
10.1128/jvi.78.3.1367-1374.2004
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发表时间：
2004-02-01
影响因子：
5.4
通讯作者：
Baines, JD
中科院分区：
文献类型：
--
作者：
Beard, PM;Duffy, C;Baines, JD
由单纯疱疹病毒1型（HSV-1）基因U（L）15和U（L）28产生的蛋白质被认为是末端酶的一部分，末端酶是一种蛋白质复合物，对于切割新合成的多联体疱疹病毒DNA和将所得基因组长度包装到预先形成的衣壳中是必需的。这项工作描述了重组形式的PU（L）15和pU（L）28的纯化，其允许计算A和B衣壳以及缺乏U（L）6编码的推定门户的衣壳中每种蛋白的平均拷贝数。平均1.0（+/-0.29 [标准差]）PU（L）15和2.4的副本B衣壳中pU（L）28的拷贝数为（+/-0.97）个，PU（L）15和1.5的（+/-0.72）副本在缺乏推定的门蛋白pU（L）6的突变衣壳中发现了（+/-0.86）拷贝的pU（L）28，并且在每个A衣壳中存在约12.0（+/-5.63）拷贝的pU（L）15和0.6（+/-0.32）拷贝的pU（L）28。这些结果表明，包装机部分由约12个拷贝的pU（L）15组成，如在A衣壳中发现的，野生型B和突变型U（L）6（-）衣壳含有不完全的切割和包装蛋白互补物。这些结果与在体外和体内不存在包装机器的情况下默认形成B衣壳的观察结果一致。相比之下，A衣壳可能是DNA包装中启动但失败的尝试的结果，导致至少部分DNA包装机器的保留。
The proteins produced by the herpes simplex virus type 1 (HSV-1) genes U(L)15 and U(L)28 are believed to form part of the terminase enzyme, a protein complex essential for the cleavage of newly synthesized, concatameric herpesvirus DNA and the packaging of the resultant genome lengths into preformed capsids. This work describes the purification of recombinant forms of PU(L)15 and pU(L)28, which allowed the calculation of the average number of copies of each protein in A and B capsids and in capsids lacking the putative portal encoded by U(L)6. On average, 1.0 (+/-0.29 [standard deviation]) copies of PU(L)15 and 2.4 (+/-0.97) copies of pU(L)28 were present in B capsids, 1.2 (+/-0.72) copies of PU(L)15 and 1.5 (+/-0.86) copies of pU(L)28 were found in mutant capsids lacking the putative portal protein pU(L)6, and approximately 12.0 (+/-5.63) Copies of pU(L)15 and 0.6 (+/-0.32) copies of pU(L)28 were present in each A capsid. These results suggest that the packaging machine is partly comprised of approximately 12 copies of pU(L)15, as found in A capsids, with wild-type B and mutant U(L)6(-) capsids containing an incomplete complement of cleavage and packaging proteins. These results are consistent with observations that B capsids form by default in the absence of packaging machinery in vitro and in vivo. In contrast, A capsids may be the result of initiated but aborted attempts at DNA packaging, resulting in the retention of at least part of the DNA packaging machinery.