Chemical Synthesis and biochemical reactivity of bacterlophage bambda pRpromoter

Abstract

By a combination of chemical and enzymatic methods, a 75 base pair DNA duplex containing the sequence of the lambda PR promoter including the ORI and 0R2 cl repressor binding sites was synthesized. The solid support phosphite triester procedure (Caruthers, M. H. et al., Cold Spring Harbor Synmo-sia on Quantitative Biology XLVII, in press) was used for the synthesis of oligonucleotides comprising the sequence. We report here an adaptation of the method to DNA synthesis in test tubes. Assembly of the oligonucleotides involved the use of T4 polynucleotide kinase and T4 DNA ligase. We show that the synthetic DNA is recognized by RNA oolymerase and cl repressor in a manner identical to the same control region contained on a restriction fragment isolated from bacteriophage lambda DNA. Our synthetic approach using chemically synthesized promoter variants is thus suitable for studies Drobing the function of promoters.