CXV. Total synthesis of the structural gene for an alanine transfer RNA from yeast. Enzymic joining to form the total DNA duplex

Abstract

The DNA duplex corresponding to the entire length (77 nucleotides) of the major yeast alanine transfer RNA has been synthesized. The duplex [A](paper CXII), corresponding to nucleotide sequence 1 to 20 and containing a single-stranded end (nucleotides 17 to 20) was joined to the duplex [B](paper CXIII), corresponding to nucleotide sequence 17 to 50 and containing single-stranded ends (nucleotides 17 to 20 and 46 to 50). The resulting duplex [A-B], nucleotide sequence 1 to 50, was characterized. The duplex [B] was also joined to [C 5] (paper CXIV), which corresponds to nucleotide sequence 56 to 77 in the presence of the “bridge” decanucleotide d-G-G-A-G-C-G-C-G-C-T (nucleotides 46 to 55) to give the duplex [B–C](nucleotide sequence 17 to 77). The entire duplex [A-B-C] was prepared in two alternative ways. In the first, preformed [B + C] was joined to the duplex [A]. In the second, preformed duplex [A+B] was joined to either the duplex [C 6](paper CXIV) or the duplex [C 5] in the presence of the decanucleotide d-[5′- 32P]-d-G-G-A-G-C-G-C-G-C-T. The duplex [A-B-C] was characterized.