The purine structure consists of a pyrimidine ring (positions 1 to 6) fused to an imidazole ring (positions 7 to 9). Adenine and guanine, the two most common purines in DNA and RNA, share this core ...

The metabolically important purines, adenine and guanine, serve as building blocks for nucleic acids and as components of cofactors for a wide variety of biochemical reactions. Adenine and guanine ...

The pyrimidines, thymine (DNA), uracil (RNA), and cytosine are shown on top while the purines, adenine and guanine, are shown at the bottom. (Image: adapted from Wikimedia Commons, public domain) The ...