ABSTRACT
Oligonucleotide fragments of the general sequence ABn, BnC and ABnC as building units for polynucleotide synthesis can be obtained by three types of reactions, namely the sequence-specific co-condensation of nucleic acid constituents, the sequence-specific degradation of copolymers and the limited addition of nucleotides to primers. Examples for these reactions are described and the scope and application of the approach discussed.
Subject(s)
Polynucleotides/chemical synthesis , Base Sequence , Deoxyribonucleases , Indicators and Reagents , Methods , Ribonucleases , Substrate SpecificityABSTRACT
When guanine and uracil form hydrogen bonds in the pairing scheme first proposed by Crick one would expect that poly(A,G) will form an unperturbed double helix with poly U at room temperature in a dilute electrolyte solution (0.1 M NaCl). We have demonstrated by Raman- and IR-spectroscopy that the secondary structure of poly(A.G) . poly U is very similar to the structure of poly A . poly U; only the thermal stability of the double helix seems slightly lower than the stability of poly A . poly U, whereas the average helix length is unaffected by the dispersed G . U base pairs. From our input ratio of guanine and adenine we estimate that about every fourth base pair is a wobble pair.
