Draper D E, Pratt C W, von Hippel P H
Proc Natl Acad Sci U S A. 1977 Nov;74(11):4786-90. doi: 10.1073/pnas.74.11.4786.
The interaction of Escherichia coli ribosomal protein S1 with a variety of RNA and DNA oligomers and polymers has been studied, using both a sedimentation technique and the quenching of intrinsic protein fluorescence upon nucleic acid binding to obtain equilibrium binding parameters. Two polynucleotide binding sites have been detected on S1: site I binds either single-stranded DNA or RNA and does not discriminate between adenine- and cytidine-containing polynucleotides, while the II binding is highly specific for RNA over DNA and shows a marked preference for cytidine polynucleotides over the corresponding adenine-containing species. On the basis of the binding properties of S1 to denatured DNA cellulose and poly(rC)-cellulose, it is demonstrated that every S1 molecule carries both a site I and a site II. Some possible implications of these results for mechanisms of protein synthesis and phage Qbeta replication are briefly considered.
利用沉降技术以及核酸结合时蛋白质固有荧光的猝灭来获得平衡结合参数,对大肠杆菌核糖体蛋白S1与多种RNA和DNA寡聚物及聚合物之间的相互作用进行了研究。在S1上检测到了两个多核苷酸结合位点:位点I可结合单链DNA或RNA,且不区分含腺嘌呤和含胞嘧啶的多核苷酸,而位点II对RNA的结合比对DNA具有高度特异性,并且对含胞嘧啶的多核苷酸比对相应的含腺嘌呤物种表现出明显的偏好。基于S1与变性DNA纤维素和聚(rC)-纤维素的结合特性,证明每个S1分子都同时带有一个位点I和一个位点II。简要考虑了这些结果对蛋白质合成机制和噬菌体Qβ复制的一些可能影响。