Simons A, Tils D, von Wilcken-Bergmann B, Müller-Hill B
Proc Natl Acad Sci U S A. 1984 Mar;81(6):1624-8. doi: 10.1073/pnas.81.6.1624.
Five DNA fragments have been cloned from yeast, chicken, and mouse DNA that titrate lac repressor in an Escherichia coli lac+ I+Z+ wild-type strain when on a multi-copy plasmid. The five repressor-binding sequences have been identified by DNA sequence determinations and DNase cleavage-inhibition patterns. They share the 14-base-pair symmetrical consensus sequence 5' T-G-T-G-A-G-C:G-C-T-C-A-C-A 3' (the colon represents the center of symmetry), which is an inverted repeat of 7 base pairs of the left half of the E. coli lac operator. A similar perfect palindromic DNA fragment--an 11-base-pair inverted repeat of the left half of the lac operator--was synthesized. The cloned synthetic DNA 5' G-A-A-T-T-G-T-G-A-G-C:G-C-T-C-A-C-A-A-T-T-C 3' binds lac repressor 8-fold more tightly than does wild-type E. coli lac operator DNA.
已从酵母、鸡和小鼠的DNA中克隆出五个DNA片段，当它们位于多拷贝质粒上时，能在大肠杆菌lac+ I+Z+野生型菌株中滴定乳糖阻遏物。通过DNA序列测定和DNase切割抑制模式确定了这五个阻遏物结合序列。它们共享14个碱基对的对称共有序列5'T-G-T-G-A-G-C:G-C-T-C-A-C-A 3'（冒号代表对称中心），这是大肠杆菌乳糖操纵子左半部分7个碱基对的反向重复序列。合成了一个类似的完美回文DNA片段——乳糖操纵子左半部分11个碱基对的反向重复序列。克隆的合成DNA 5'G-A-A-T-T-G-T-G-A-G-C:G-C-T-C-A-C-A-A-T-T-C 3'与乳糖阻遏物的结合比野生型大肠杆菌乳糖操纵子DNA紧密8倍。
