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.

The crucial nature of the contacts between cytosine methyl groups and the protein is ... oriented relative to the sequence on a single DNA molecule because the CpG on a given strand will either ...

Cytosine can undergo chemical modifications that play crucial roles in gene regulation and epigenetics. The most common modification is the addition of a methyl group to carbon 5, forming ...

DNA methylation is a fundamental epigenetic mechanism in which a methyl group is added onto a nucleotide, commonly cytosine. DNA methylation affects many biological processes, including gene ...

DNA methylation is a process in which a methyl group is attached to the cytosine base of the DNA molecule, and a major way that DNA is epigenetically marked. Epigenetic modifications can act as on ...

thymine (T), adenine (A), cytosine (C), and guanine (G). These bases are the rungs of the DNA ladder. (It takes two bases to form a rung -- one for each side of the ladder.) A sugar molecule, a ...

and the amount of guanine is equal to the amount of cytosine in a double-stranded DNA molecule. This 1:1 ratio of A:T and G:C is crucial for maintaining the structure and stability of DNA.

This reaction, deamination, is about twice as likely to happen when a cytosine is chemically tagged by the addition of a molecule known as a methyl group to create 5-methylcytosine, which occurs ...