Milman G, Goldstein J, Scolnick E, Caskey T
Proc Natl Acad Sci U S A. 1969 May;63(1):183-90. doi: 10.1073/pnas.63.1.183.
Throughout extensive purification, the release factors R(1) and R(2) each behave as a single molecular species with alternate codon recognition (R(1), UAA or UAG; R(2), UAA or UGA). The release of f[(3)H]methionine from f[(3)H]-Met-tRNA.AUG.ribosome complex requires R factor and terminator codon and does not appear to require tRNA or transfer factors T and G. Purification of the components of the release assay has enabled identification of a protein factor S in the 55-80 per cent ammonium sulfate fraction of E. coli B supernatant fraction which stimulates the rate but not the extent of release dependent upon R factor and appropriate termination codon. The S factor has properties similar to T, but further purification is required to determine the nature and function of S in peptide chain termination.
在广泛的纯化过程中,释放因子R(1)和R(2)各自表现为单一分子物种,具有交替的密码子识别能力(R(1)识别UAA或UAG;R(2)识别UAA或UGA)。从f[(3)H]-Met-tRNA.AUG.核糖体复合物中释放f[(3)H]甲硫氨酸需要R因子和终止密码子,似乎不需要tRNA或转移因子T和G。释放测定成分的纯化已使得能够在大肠杆菌B上清液部分55%至80%硫酸铵级分中鉴定出一种蛋白质因子S,它能刺激依赖于R因子和适当终止密码子的释放速率,但不影响释放程度。S因子具有与T因子相似的特性,但需要进一步纯化以确定S在肽链终止中的性质和功能。