Ahrens C H, Rohrmann G F
Department of Agricultural Chemistry, Oregon State University, Corvallis 97331-7301, USA.
J Gen Virol. 1996 May;77 ( Pt 5):825-37. doi: 10.1099/0022-1317-77-5-825.
Regions of the genome of the Orgyia pseudotsugata multinucleocapsid nuclear polyhedrosis virus (OpMNPV) containing the DNA polymerase and helicase genes were sequenced. The DNA polymerase and helicase genes encode predicted proteins of 985 (112.6 kDa) and 1223 (140.5 kDa) amino acids and exhibited 63 % and 59 % amino acid identity, respectively, with their homologues in the Autographa californica MNPV (AcMNPV). The influence of sequence variation between the OpMNPV and AcMNPV DNA polymerase and helicase was investigated by employing gene substitution experiments in transient replication assays in Lymantria dispar and Spodoptera frugiperda cells. The DNA polymerase gene appeared to be interchangeable in this assay; both the AcMNPV and OpMNPV DNA polymerase supported high levels of replication of an origin-containing reporter plasmid when substituted for their homologue and cotransfected with a set of heterologous essential and stimulatory replication genes into uninfected insect cells. However, the OpMNPV helicase failed to support replication when it replaced the AcMNPV helicase from the set of AcMNPV replication genes cotransfected into S. frugiperda cells. In contrast, the AcMNPV helicase gene supported about 50% of the level of replication when substituted for its homologue in the OpMNPV set of replication genes.
对云杉毒蛾多核衣壳核型多角体病毒（OpMNPV）基因组中包含DNA聚合酶和解旋酶基因的区域进行了测序。DNA聚合酶和解旋酶基因编码的预测蛋白分别含有985个氨基酸（112.6 kDa）和1223个氨基酸（140.5 kDa），与苜蓿银纹夜蛾多核衣壳核型多角体病毒（AcMNPV）中的同源蛋白分别具有63%和59%的氨基酸同一性。通过在舞毒蛾和草地贪夜蛾细胞的瞬时复制试验中进行基因替换实验，研究了OpMNPV和AcMNPV DNA聚合酶和解旋酶之间序列变异的影响。在该试验中，DNA聚合酶基因似乎是可互换的；当用AcMNPV和OpMNPV DNA聚合酶替代其同源基因，并与一组异源必需和刺激复制基因共转染到未感染的昆虫细胞中时，二者都能支持含有复制起点的报告质粒的高水平复制。然而，当OpMNPV解旋酶取代共转染到草地贪夜蛾细胞中的AcMNPV复制基因组中的AcMNPV解旋酶时，它无法支持复制。相反，当AcMNPV解旋酶基因替代OpMNPV复制基因组中的同源基因时，它能支持约50%的复制水平。
