title: Preparation of triple-block DNA polymers using recombinant DNA techniques.
abstract: The construction of several recombinant plasmid derivatives containing novel triple-block DNA sequence insertions is described. The protocol for these constructions involves synthesis of a heterogenous mixture of block oligomer duplexes, : formula: (see text), using pancreatic deoxyribonuclease and terminal transferase. The synthetic duplexes were mixed with linearized and dG-tailed vectors and the DNA mixture used to transform E. coli. Triple-block sequences of the type dGidAjdCk.dGkdTjdCi, characterized by DNA sequencing, were inserted into the Bam HI site of pBR322 and next to the lac wild-type and UV5 promoter regions in pRW26 and pRW28. Similarly, sequences were inserted into the Sma I site of pACYC189 and could be excised by cleavage with Sma I since the procudure regenerates the recognition site. The approach provides a technique for the synthesis of a large family of defined sequence triple-block polymers in essentially unlimited amounts. Although these inserts contain sequences which have the potential for forming stable hairpin structures, the recombinant plasmids are stable and appear to replicate normally.
mesh_terms: D000818:Animals; D001483:Base Sequence; D002417:Cattle; D055598:Chemical Phenomena; D002621:Chemistry; D004247:DNA; D004254:DNA Nucleotidyltransferases; D004262:DNA Restriction Enzymes; D004274:DNA, Recombinant; D009838:Oligodeoxyribonucleotides; D010957:Plasmids; D013950:Thymus Gland / Q000201:enzymology
chemical_list: D004274:DNA, Recombinant; D009838:Oligodeoxyribonucleotides; D004247:DNA; D004254:DNA Nucleotidyltransferases; D004262:DNA Restriction Enzymes