title: Non-enzymic template-directed synthesis on RNA random copolymers. Poly(C, G) templates.
abstract: Poly(C, G) random copolymer templates direct the oligomerization of 2-Me-ImpG and 2-MeImpC, resulting in the production of a variety of oligo(G, C)s. The efficiency of monomer incorporation into newly synthesized oligomers is greater for 2-MeImpG than for 2-MeImpC, and decreases for both monomers as the guanine content of the template increases. The relatively low efficiency of oligomerization on guanine-rich templates is largely a consequence of intra- and intermolecular template self-structure. The problem of template self-structure is clearly a major obstacle to the development of a system of self-replicating polynucleotides. The distribution of oligomeric products can be characterized in detail using high-pressure liquid chromatography on an RPC-5 column. Oligomers are separated on the basis of chain length, base composition and phosphodiester-linkage isomerism. Oligomers up to about the 12-mer, with base composition Gn, Gn-1C and Gn-2C2, have been identified. The 3' to 5' regiospecificity of the products is high, particularly for oligomers with base composition Gn.
mesh_terms: D002851:Chromatography, High Pressure Liquid; D003568:Cytidine Monophosphate / Q000031:analogs & derivatives / Q000378:metabolism; D006157:Guanosine Monophosphate / Q000031:analogs & derivatives / Q000378:metabolism; D009841:Oligonucleotides / Q000096:biosynthesis; D011066:Poly C / Q000378:metabolism*; D011068:Poly G / Q000378:metabolism*; D011131:Polyribonucleotides / Q000378:metabolism*; D012313:RNA / Q000096:biosynthesis*; D013698:Templates, Genetic
chemical_list: D009841:Oligonucleotides; D011131:Polyribonucleotides; D011068:Poly G; C008961:poly G-poly C; D011066:Poly C; D012313:RNA; C036896:guanosine 5'-phospho-2-methylimidazolide; D006157:Guanosine Monophosphate; C043331:cytidine 5'-phospho-2-methylimidazolide; D003568:Cytidine Monophosphate