Truden J L, Franklin R M
J Virol. 1972 Jan;9(1):75-84. doi: 10.1128/JVI.9.1.75-84.1972.
Synthesis of viral ribonucleic acid (RNA) polymerase, maturation protein, and coat protein in Escherichia coli infected with bacteriophage R17 occurs mainly on polysomes containing four or more ribosomes. The 30S ribosomal subunits through trimer-size polysomes, which are associated with all of the R17-specific proteins and are predominant in the infected cell, synthesize only coat protein. These structures may accumulate as products derived from larger polysomes as a result of failure in the release of nascent polypeptides after termination of chain growth. Appreciable amounts of viral coat protein remain attached to ribosomes and polysomes during R17 bacteriophage replication, supporting the hypothesis of the repressor role of this protein. The time course of synthesis of virus-specific proteins obtained from the polysomes of infected cells demonstrated regulated R17 messenger RNA translation consistent with the idea that coat protein is preferentially synthesized whereas the synthesis of noncoat proteins is suppressed.
感染噬菌体R17的大肠杆菌中，病毒核糖核酸（RNA）聚合酶、成熟蛋白和衣壳蛋白的合成主要发生在含有四个或更多核糖体的多聚核糖体上。30S核糖体亚基通过三聚体大小的多聚核糖体（这些多聚核糖体与所有R17特异性蛋白相关联，且在感染细胞中占主导）仅合成衣壳蛋白。由于链生长终止后新生多肽释放失败，这些结构可能作为来自更大的多聚核糖体的产物而积累。在R17噬菌体复制过程中，相当数量的病毒衣壳蛋白仍附着在核糖体和多聚核糖体上，支持了这种蛋白具有阻遏作用的假说。从感染细胞的多聚核糖体中获得的病毒特异性蛋白的合成时间进程表明，R17信使RNA的翻译受到调控，这与衣壳蛋白优先合成而非衣壳蛋白合成受到抑制的观点一致。
