Krisch H M, Allet B
Proc Natl Acad Sci U S A. 1982 Aug;79(16):4937-41. doi: 10.1073/pnas.79.16.4937.
We have determined the nucleotide sequence of a cloned segment of the bacteriophage T4D chromosome, which contains the regulatory sequences and the structural gene (gene 32) for the single-stranded DNA binding protein (gp32). The amino acid sequence predicted by translation of the structural gene agrees well with that published for gp32 [Williams, K. R., Lo-Presti, M. B., Setoguchi, M. & Konigsberg, W. H. (1980) Proc. Natl. Acad. Sci. USA 77, 4614-4617]. To localize the nucleotide sequence involved in translational self-regulation of gene 32, we have constructed a series of plasmids in which gene 32 is fused to an amino-terminal deletion mutant of the beta-galactosidase gene of Escherichia coli. Expression of a beta-galactosidase fusion protein that contains only the first seven amino acids of gp32 is still repressed by gp32. The ribosomal binding site of gene 32 is flanked by a repetitive A+T-rich sequence. Preferential and cooperative binding of gp32 to this region of its mRNA could inhibit translation initiation and, thus, would account for the autoregulation.
我们已经确定了噬菌体T4D染色体一个克隆片段的核苷酸序列，该片段包含单链DNA结合蛋白（gp32）的调控序列和结构基因（基因32）。通过结构基因翻译预测的氨基酸序列与已发表的gp32序列[Williams, K. R., Lo-Presti, M. B., Setoguchi, M. & Konigsberg, W. H. (1980) Proc. Natl. Acad. Sci. USA 77, 4614-4617]非常吻合。为了定位参与基因32翻译自我调控的核苷酸序列，我们构建了一系列质粒，其中基因32与大肠杆菌β-半乳糖苷酶基因的氨基末端缺失突变体融合。仅包含gp32前七个氨基酸的β-半乳糖苷酶融合蛋白的表达仍受gp32抑制。基因32的核糖体结合位点两侧是富含A+T的重复序列。gp32与其mRNA的该区域的优先和协同结合可能会抑制翻译起始，因此可以解释这种自我调控。
