Adenine molecule. Computer artwork showing the structure of a molecule of the nucleobase adenine. Atoms are colour-coded spheres: carbon (green), nitrogen (blue), and oxygen (white), with the bonds between them as rods. Adenine is one of the four nitrogenous bases found in the nucleic acid molecules DNA (deoxyribonucleic acid) and RNA (ribonucleic acid), which form complementary pairs. Adenine's complementary base in DNA is thymine and RNA is uracil.