Guarente L, Ptashne M
Proc Natl Acad Sci U S A. 1981 Apr;78(4):2199-203. doi: 10.1073/pnas.78.4.2199.
Hybrid genes between the Escherichia coli lacZ gene and the iso-1-cytochrome c (CYC1) gene of Saccharomyces cerevisiae were constructed by recombination in vitro. Each of the hybrid genes encodes a chimeric protein with a cytochrome c moiety at the amino terminus and an active beta-galactosidase (beta-D-galactoside galactohydrolase, EC 3.2.1.23) moiety at the carboxy terminus. When these hybrids are introduced into S. cerevisiae on plasmid vectors, they direct synthesis of beta-galactosidase. beta-Galactosidase levels directed by one such plasmid display the pattern of regulation normally seen for cytochrome c (i.e., a reduction of synthesis in cells grown in glucose). This plasmid contains one codon of CYC1 fused to lacZ, and the fused gene is preceded by the 1100 nucleotides that lie upstream from CYC1. An analysis of deletions in the upstream DNA suggests that sequences required for efficient transcription initiation of CYC1 lie within the DNA segment 250--700 base pairs upstream from the start of the CYC1 coding sequence. This region is at least 130 base pairs upstream from the "Hogness box" sequence that precedes the CYC1 coding sequence.
通过体外重组构建了大肠杆菌乳糖Z基因与酿酒酵母同工-1-细胞色素c（CYC1）基因之间的杂种基因。每个杂种基因编码一种嵌合蛋白，其氨基末端带有细胞色素c部分，羧基末端带有活性β-半乳糖苷酶（β-D-半乳糖苷半乳糖水解酶，EC 3.2.1.23）部分。当这些杂种通过质粒载体导入酿酒酵母时，它们指导β-半乳糖苷酶的合成。由一种这样的质粒指导的β-半乳糖苷酶水平显示出通常在细胞色素c中看到的调节模式（即，在葡萄糖中生长的细胞中合成减少）。该质粒包含一个与lacZ融合的CYC1密码子，并且融合基因之前是位于CYC1上游的1100个核苷酸。对上游DNA缺失的分析表明，CYC1有效转录起始所需的序列位于CYC1编码序列起始上游250-700碱基对的DNA片段内。该区域位于CYC1编码序列之前的“霍格内斯盒”序列上游至少130个碱基对处。
