Vincent R D, Hofmann T J, Zassenhaus H P
Department of Microbiology, St Louis University Medical Center, MO 63104.
Nucleic Acids Res. 1988 Apr 25;16(8):3297-312. doi: 10.1093/nar/16.8.3297.
The DNA sequence and studies on the expression of the NUC1 gene from Saccharomyces cerevisiae are presented. The NUC1 locus is located in the distal portion of the left arm of Chromosome X and encodes the major nuclease found in mitochondria. The inferred amino acid sequence of NUC1 predicts that the nuclease is basic, rich in prolines, of average hydrophobicity, and has a molecular weight for the primary translation product of 37,209 daltons. NUC1 is very poorly expressed, consistent with the codon usage bias determined from the DNA sequence and our previous determination of the number of enzyme molecules per cell. Mapping of the 5' terminus of the NUC1 mRNA reveals that the mRNA has a long 400 base untranslated leader in which are found three open reading frames, each initiated by an AUG. The possibility that these upstream open reading frames contribute to the poor expression of the NUC1 gene is discussed.
本文介绍了酿酒酵母NUC1基因的DNA序列及其表达研究。NUC1基因座位于X染色体左臂的远端，编码线粒体中发现的主要核酸酶。NUC1的推断氨基酸序列预测该核酸酶呈碱性，富含脯氨酸，具有平均疏水性，其初级翻译产物的分子量为37209道尔顿。NUC1的表达非常低，这与根据DNA序列确定的密码子使用偏好以及我们之前对每个细胞中酶分子数量的测定结果一致。对NUC1 mRNA 5'末端的定位揭示，该mRNA有一个长400个碱基的非翻译前导序列，其中有三个开放阅读框，每个都由AUG起始。文中讨论了这些上游开放阅读框导致NUC1基因低表达的可能性。
