Guo Z, Russo P, Yun D F, Butler J S, Sherman F
Department of Biochemistry, University of Rochester School of Medicine and Dentistry, NY 14642, USA.
Proc Natl Acad Sci U S A. 1995 May 9;92(10):4211-4. doi: 10.1073/pnas.92.10.4211.
The cyc1-512 mutation is a 38-bp deletion in the 3' untranslated region of the CYC1 gene, which encodes iso-1-cytochrome c in Saccharomyces cerevisiae. This deletion caused a 90% reduction in the levels of the CYC1 mRNA and protein because of the absence of the normal 3' end-forming signal. Although the 3' end-forming signal was not defined by previous analyses, we report that concomitant alteration by base-pair substitution of three 3' end-forming signals within and adjacent to the 38-bp region produced the same phenotype as the cyc1-512 mutation. Furthermore, these signals appear to be related to the previously identified 3' end-forming signal TATATA. A computer analysis revealed that TATATA and related sequences were present in the majority of 3' untranslated regions of yeast genes. Although TATATA may be the strongest and most frequently used signal in yeast genes, the CYC1+ gene concomitantly employed the weaker signals TT-TATA, TATGTT, and TATTTA, resulting in a strong signal.
cyc1-512突变是酿酒酵母中编码同工型细胞色素c1的CYC1基因3'非翻译区的一个38bp缺失。由于缺乏正常的3'末端形成信号，这种缺失导致CYC1 mRNA和蛋白质水平降低了90%。尽管先前的分析未确定3'末端形成信号，但我们报告称，对38bp区域内及相邻的三个3'末端形成信号进行碱基对替换的同时改变，产生了与cyc1-512突变相同的表型。此外，这些信号似乎与先前鉴定的3'末端形成信号TATATA有关。计算机分析显示，TATATA及相关序列存在于酵母基因的大多数3'非翻译区。尽管TATATA可能是酵母基因中最强且最常用的信号，但CYC1+基因同时使用了较弱的信号TT-TATA、TATGTT和TATTTA，从而形成了一个强信号。
