Hippenmeyer P J, Grandgenett D P
Virology. 1984 Sep;137(2):358-70. doi: 10.1016/0042-6822(84)90228-9.
The NH2-terminal amino acid sequence of the pp32 DNA binding protein has been determined, thus establishing its precise coding region in the polymerase gene of Rous sarcoma virus. Specific mutations were constructed in molecularly cloned Prague A DNA near the NH2- and COOH-termini of pp32 and the effects were assayed by transfection on chick embryo fibroblasts. Out-of-frame deletions at both sites and an in-frame deletion near the NH2 terminus rendered the DNA noninfectious and transformation negative. Single point mutations near the NH2 terminus reduced the transfection efficiency and the rate of virus replication. Biochemical studies indicated that the RNA-directed DNA polymerase and RNase H activities of the mutant viruses were not affected but the processing of the viral beta polypeptide was altered.
已确定pp32 DNA结合蛋白的氨基末端氨基酸序列，从而确定了其在劳氏肉瘤病毒聚合酶基因中的精确编码区域。在分子克隆的布拉格A DNA中，在pp32的氨基末端和羧基末端附近构建了特定突变，并通过转染鸡胚成纤维细胞来检测其效果。两个位点的框外缺失以及氨基末端附近的框内缺失使DNA无感染性且转化阴性。氨基末端附近的单点突变降低了转染效率和病毒复制率。生化研究表明，突变病毒的RNA指导的DNA聚合酶和RNase H活性未受影响，但病毒β多肽的加工过程发生了改变。
