Carstens E B, Krebs A, Gallerneault C E
J Virol. 1986 May;58(2):684-8. doi: 10.1128/JVI.58.2.684-688.1986.
We compared the DNA sequence of the Autographa californica nuclear polyhedrosis virus polyhedrin gene with that of the polyhedrin gene from a morphology mutant called M5. A single point mutation was found at the BamHI restriction site within the polyhedrin coding sequence. This point mutation caused a substitution of leucine for proline at amino acid 58 in the M5 polyhedrin. This point mutation was shown to be responsible for both the appearance of cubic polyhedra and the altered mobility of the polypeptide on sodium dodecyl sulfate-polyacrylamide gels by transferring the M5 polyhedrin gene to the wild-type virus by cotransfection. Recombinants were found which assembled cubic polyhedra in infected cells, had the BamHI restriction site missing, and had an altered mobility of their polyhedrin polypeptide. Computed-predicted secondary-structure analysis indicated that the amino acid at position 58 could be critical to the proper folding of polyhedrin.
我们将苜蓿银纹夜蛾核型多角体病毒多角体蛋白基因的DNA序列与一个名为M5的形态突变体的多角体蛋白基因序列进行了比较。在多角体蛋白编码序列内的BamHI酶切位点发现了一个单点突变。该点突变导致M5多角体蛋白第58位氨基酸处的脯氨酸被亮氨酸取代。通过共转染将M5多角体蛋白基因转移到野生型病毒中，结果表明该点突变既导致了立方多角体的出现，也导致了该多肽在十二烷基硫酸钠-聚丙烯酰胺凝胶上迁移率的改变。发现重组体在感染细胞中组装成立方多角体，缺少BamHI酶切位点，并且其多角体蛋白多肽的迁移率发生了改变。计算机预测的二级结构分析表明，第58位的氨基酸可能对多角体蛋白的正确折叠至关重要。
