title: Non-enzymatic template-directed synthesis on RNA random copolymers. Poly(C,A) templates.
abstract: Poly(C,A) random copolymer templates direct the oligomerization of 2-MeImpG (2-MeImpX is the 5'-phospho-2-methylimidazolide of the nucleoside X) and 2-MeImpU, resulting in the production of a variety of oligo (G,U)s. This reaction is less efficient than comparable reactions involving poly(C,U) or poly(C,G) templates. The efficiency of monomer incorporation into newly synthesized oligomers is lower for 2-MeImpU than 2-MeImpG, and cannot be improved by increasing the concentration of 2-MeImpU relative to 2-MeImpG. This suggests that RNA templates containing runs of consecutive adenine residues would not be suitable for use in a chemical self-replicating system. 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 13-mer, with base composition Gn, Gn-1, U, and Gn-2, U2, have been identified.
authors: Salk Institute for Biological Studies, San Diego, CA 92138.
authors: G F
authors: GF
authors: Joyce
authors: L E
authors: LE
authors: Orgel
mesh_terms: D002851:Chromatography, High Pressure Liquid; D006157:Guanosine Monophosphate / Q000031:analogs & derivatives / Q000378:metabolism; D009841:Oligonucleotides / Q000096:biosynthesis; D011061:Poly A / Q000378:metabolism*; D011066:Poly C / Q000378:metabolism*; D011131:Polyribonucleotides / Q000378:metabolism*; D012313:RNA / Q000096:biosynthesis*; D013698:Templates, Genetic; D014542:Uridine Monophosphate / Q000031:analogs & derivatives / Q000378:metabolism
chemical_list: D009841:Oligonucleotides; D011131:Polyribonucleotides; D011061:Poly A; C023794:poly(A-C); D011066:Poly C; D012313:RNA; C036896:guanosine 5'-phospho-2-methylimidazolide; D006157:Guanosine Monophosphate; C057426:uridine 5'-phospho-2-methylimidazolide; D014542:Uridine Monophosphate