HYBRIDIZATION OF 2 OLIGODEOXYNUCLEOTIDES TO BOTH STRANDS OF AN RNA HAIRPIN STRUCTURE INCREASES THE EFFICIENCY OF RNA-DNA DUPLEX FORMATION

Hybridization of two oligodeoxyribonucleotides (ON1 and ON2), compleme ntary to opposite strands of the apical domain of Escherichia coli 4.5 S RNA, was studied. ON1, complementary to bases 58-71, was not able to form a stable RNA-DNA hybrid whereas ON2, complementary to bases 38- 53, was. Addition of both oligonucleotides at the same time resulted i n the formation of a ternary complex permitting hybridization of ON1 a nd increasing hybridization of ON2. Under this condition, binary compl exes of ON1 or ON2 with 4.5S RNA were not observed. The. data demonstr ate that hybridization of oligonucleotides to both strands of an RNA h airpin structure increases the efficiency of hybridization of either o ligonucleotide.