Guo Z, Sherman F
Department of Biochemistry, University of Rochester School of Medicine and Dentistry, New York 14642, USA.
Mol Cell Biol. 1996 Jun;16(6):2772-6. doi: 10.1128/MCB.16.6.2772.
The following three elements were previously shown to be required for 3'-end formation of mRNA in the yeast Saccharomyces cerevisiae: (i) the efficiency element TATATA or related sequences, which function by enhancing the efficiency of downstream positioning elements; (ii) the positioning element AATAAA or related sequences, which position the poly(A) site; and (iii) the actual poly(A) site, which is usually Py(A)n. In this study, we synthesized a 39-pb poly(A) signal that contained the optimum sequences of these three elements. By inserting the synthetic 3'-end-forming signal into various positions of a CYC1-lacZ fusion gene, we showed that truncated transcripts of the expected sizes were generated. Furthermore, the poly(A) sites of the truncated transcripts were mapped to the expected poly(A) site within the synthetic signal. Our findings establish that the three elements are not only necessary but also sufficient for mRNA 3'-end formation in S. cerevisiae.
先前的研究表明，酿酒酵母中mRNA 3'端形成需要以下三个元件：（i）效率元件TATATA或相关序列，其通过增强下游定位元件的效率发挥作用；（ii）定位元件AATAAA或相关序列，其定位poly（A）位点；（iii）实际的poly（A）位点，通常为Py（A）n。在本研究中，我们合成了一个包含这三个元件最佳序列的39个碱基对的poly（A）信号。通过将合成的3'端形成信号插入CYC1-lacZ融合基因的不同位置，我们发现产生了预期大小的截短转录本。此外，截短转录本的poly（A）位点被定位到合成信号内预期的poly（A）位点。我们的研究结果表明，这三个元件不仅是酿酒酵母中mRNA 3'端形成所必需的，而且也是充分的。
