Huang W M, Ao S Z, Casjens S, Orlandi R, Zeikus R, Weiss R, Winge D, Fang M
Department of Cellular, Viral and Molecular Biology, University of Utah Medical Center, Salt Lake City 84132.
Science. 1988 Feb 26;239(4843):1005-12. doi: 10.1126/science.2830666.
A 50-nucleotide untranslated region is shown to be present within the coding sequence of Escherichia coli bacteriophage T4 gene 60, which encodes one of the subunits for its type II DNA topoisomerase. This interruption is part of the transcribed messenger RNA and appears not to be removed before translation. Thus, the usual colinearity between messenger RNA and the encoded protein sequence apparently does not exist in this case. The interruption is bracketed by a direct repeat of five base pairs. A mechanism is proposed in which folding of the untranslated region brings together codons separated by the interruption so that the elongating ribosome may skip the 50 nucleotides during translation. The alternative possibility, that the protein is efficiently translated from a very minor and undetectable form of processed messenger RNA, seems unlikely, but has not been completely ruled out.
研究表明，在大肠杆菌噬菌体T4基因60的编码序列中存在一个50个核苷酸的非翻译区，该基因编码其二型DNA拓扑异构酶的一个亚基。这种中断是转录信使RNA的一部分，并且在翻译前似乎未被去除。因此，在这种情况下，信使RNA与编码的蛋白质序列之间通常的共线性显然不存在。该中断由一个5个碱基对的直接重复序列界定。提出了一种机制，即非翻译区的折叠将被中断隔开的密码子聚集在一起，以便延长中的核糖体在翻译过程中可以跳过这50个核苷酸。另一种可能性，即蛋白质从一种非常少量且无法检测到的加工后信使RNA形式高效翻译而来，似乎不太可能，但尚未被完全排除。
