Deoxyribonucleic acids (DNA) and related compounds. XIII. Synthesis of DNA duplexes containing a ribosome binding site.

Abstract
To investigate the efficiency of expression of synthetic genes, deoxyribonucleic acid (DNA) duplexes (33-37 base pairs) containing the ribosome binding site (S.D. [Shine-Dalgarno] sequence) for trpL and appropriate termini were synthesized. This involved chemical synthesis of 8 oligonucleotides with chain lengths of 16-19 by the solid-phase phosphotriester method followed by enzymatic joining with DNA ligase. The duplexes were designed to replace a restriction fragment from a plasmid containing the trp promoter and a synthetic human growth hormone gene. The S.D. sequence in these duplexes was located upstream from a Cla I site to make a distance of 9, 11 or 13 bases from the initiation signal (ATG).