Michel B, Zinder N D
Rockefeller University, New York, NY 10021.
Nucleic Acids Res. 1989 Sep 25;17(18):7333-44. doi: 10.1093/nar/17.18.7333.
We have investigated the binding of the f1 single-stranded DNA-binding protein (gene V protein) to DNA oligonucleotides and RNA synthesized in vitro. The first 16 nucleotides of the f1 gene II mRNA leader sequence were previously identified as the gene II RNA-operator; the target to which the gene V protein binds to repress gene II translation. Using a gel retardation assay, we find that the preferential binding of gene V protein to an RNA carrying the gene II RNA-operator sequence is affected by mutations which abolish gene II translational repression in vivo. In vitro, gene V protein also binds preferentially to a DNA oligonucleotide whose sequence is the DNA analog of the wild-type gene II RNA-operator. Therefore, the gene V protein recognizes the gene II mRNA operator sequence when present in either an RNA or DNA context.
我们研究了f1单链DNA结合蛋白（基因V蛋白）与体外合成的DNA寡核苷酸和RNA的结合情况。f1基因II mRNA前导序列的前16个核苷酸先前被鉴定为基因II RNA操纵子；基因V蛋白结合以抑制基因II翻译的靶标。使用凝胶阻滞试验，我们发现基因V蛋白与携带基因II RNA操纵子序列的RNA的优先结合受到体内消除基因II翻译抑制的突变的影响。在体外，基因V蛋白也优先结合一种DNA寡核苷酸，其序列是野生型基因II RNA操纵子的DNA类似物。因此，基因V蛋白在RNA或DNA环境中都能识别基因II mRNA操纵子序列。
