Ribonucleic acid (RNA) is a linear molecule composed of four types of smaller molecules called ribonucleotide bases: adenine (A), cytosine (C), guanine (G), and uracil (U). RNA is often compared ...

IN the nucleic acids, cytosine is connected to a sugar residue through N 1 of the pyrimidine ring. Here we describe the results of an X-ray diffraction analysis of crystals of N 1-methyl cytosine.