MUTANTS OF YEAST INITIATING TRANSLATION OF ISO-1-CYTOCHROME-C WITHIN A REGION SPANNING 37 NUCLEOTIDES
MUTANTS OF YEAST INITIATING TRANSLATION OF ISO-1-CYTOCHROME-C WITHIN A REGION SPANNING 37 NUCLEOTIDES
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DOI：
10.1016/0092-8674(80)90249-4
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发表时间：
1980-01-01
期刊：
影响因子：
64.5
通讯作者：
SCHWEINGRUBER, AM
中科院分区：
文献类型：
--
作者：
SHERMAN, F;STEWART, JW;SCHWEINGRUBER, AM
一株特殊构建的酵母菌株cyc 1 -345。酿酒酵母分离在沿着mRNA延伸区域沿着的不同位点启动异-1-细胞色素c翻译的回复突变体。当翻译起始于对应于氨基酸位置-3、-2、3和5的异常位点以及正常位置-1时，异-1-细胞色素c的正常量发生;当翻译起始于异常位置9时，正常量的20%发生。cyc 1 -345回复突变体的这些结果表明，异-1-细胞色素c的翻译可以在跨越25个核苷酸的区域内的任何位点以正常效率启动。因为在突变体中起始于9位的较低量的短iso-1-细胞色素c可能不一定反映翻译的低效率，看来翻译可以在37个核苷酸区域内的任何位点以正常或接近正常的效率起始，并且可能在正常起始密码子之前和之后的任何位点。这些结果证实，对于起始密码子5“的特定序列没有绝对的要求，并且与我们先前的建议一致，即翻译起始于最接近mRNA 5”末端的AUG密码子。
A specially constructed strain, cyc1-345, of the yeast S. cerevisiae was was used to isolate revertants that initiated translation of iso-1-cytochrome c at various sites along an extended region of the mRNA. Normal amounts of iso-1-cytochrome c occurred when translation initiated at the abnormal sites corresponding to amino acid positions -3, -2, 3 and 5, as well as the normal position -1; 20% of the normal amounts occurred when translation initiated at the abnormal position 9. These results with cyc1-345 revertants indicate that translation of iso-1-cytochrome c can initiate with the normal efficiency at any site within the region spanning 25 nucleotides. Because the lower amount of the short iso-1-cytochrome c in the mutant initiating at position 9 may not necessarily reflect an inefficiency of translation, it appears that translation can initiate with normal or near-normal efficiencies at any site within a 37 nucleotide region, and presumably at any site preceding and following that of the normal initiation codon. These results establish that there is no absolute requirement for a particular sequence 5'' to the initiation codon, and are consistent with our previous suggestion that translation starts at the AUG codon closest to the 5'' end of the mRNA.