RNA composition and base pairing.
If RNA may contain a small proportion of adenine-guanine base pairs, these could interrupt the continuity of helical structure in a polynucleotide, in keeping with current theories of RNA structure, and could also account for the experimentally observed tendency for 6-amino bases to equal 6-keto bases and for purines to exceed pyrimidines.
D000225:Adenine; D055598:Chemical Phenomena; D002621:Chemistry; D006147:Guanine; D011687:Purines; D011743:Pyrimidines; D012313:RNA
D011687:Purines; D011743:Pyrimidines; D006147:Guanine; D012313:RNA; D000225:Adenine