Abstract
We have studied the template-directed oligomerization on polycytidylic acid of the 5′-phosphoro(2-methyl)imidazolides of a number of analogues of guanosine. None of the analogues reacted as efficiently as the original guanosine compound, and only the 7-deazaguanosine analogue gives a detectable yield of oligomers. Similar results are described for a reaction involving the intramolecular template-directed elongation of a short oligocytidylate primer.
Oligocytidylates containing five or more cytidylate residues are extended on the single-stranded regions of poly(G). In the present study we show that these oligocytidylates are extended efficiently by reaction with cytidine-5′-phosphoro(2-methyl) imidazolide on a poly(7-deazaguanylic acid) template. The products are considerably longer than those obtained using a polyguanylic acid template. We believe that the formation of a tetrahelix inhibits the latter reaction, while poly(7-deazaguanylate) does not aggregate and, therefore, acts as a more efficient template. This work identifies for the first time a pair of homopolymers each of which facilitates the template-directed elongation of the other.
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Correspondence to: L.E. Orgel
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Rembold, H., Robins, R.K., Seela, F. et al. Polycytidylate and poly(7-deazaguanylate): A pair of complementary templates. J Mol Evol 38, 211–214 (1994). https://doi.org/10.1007/BF00176083
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DOI: https://doi.org/10.1007/BF00176083