What is special about cytosine?

Cytosine has the unique property in that it binds in the double helix opposite a guanine, one of the other nucleotides. Cytosine has one other interesting property that none of the other nucleotides have, is that very often in the cell, cytosine can have an extra chemical attached to them, a methyl group.

Why does cytosine get methylated?

Cytosine methylation is a common form of post-replicative DNA modification seen in both bacteria and eukaryotes. Modified cytosines have long been known to act as hotspots for mutations due to the high rate of spontaneous deamination of this base to thymine, resulting in a G/T mismatch.

How is cytosine methylated?

Adenine or cytosine methylation are mediated by restriction modification systems of many bacteria, in which specific DNA sequences are methylated periodically throughout the genome. A methylase is the enzyme that recognizes a specific sequence and methylates one of the bases in or near that sequence.

What is a cytosine residue?

DNA contains combinations of four nucleotides which include cytosine, guanine, thymine and adenine. These modified cytosine residues usually lie next to a guanine base (CpG methylation) and the result is two methylated cytosines positioned diagonally to each other on opposite strands of DNA.

What is the purpose of cytosine?

A chemical compound that is used to make one of the building blocks of DNA and RNA. It is a type of pyrimidine. Structure of DNA.

Why is cytosine so important?

Cytosine, a nitrogenous base derived from pyrimidine that occurs in nucleic acids, the heredity-controlling components of all living cells, and in some coenzymes, substances that act in conjunction with enzymes in chemical reactions in the body.

Is bacterial DNA methylated?

Like many eukaryotes, bacteria make widespread use of postreplicative DNA methylation for the epigenetic control of DNA-protein interactions. Unlike eukaryotes, however, bacteria use DNA adenine methylation (rather than DNA cytosine methylation) as an epigenetic signal.

What is the function of cytosine?

Does cytosine have oxygen?

Structure of the cytosine-guanine base pair, with the oxygen atoms shown in red, nitrogen in blue, carbon in gray and hydrogen in white. The hydrogen bonds are indicated by the dashed lines and indicated as (1), (2) and (3).

What are the elements in cytosine?

Cytosine is a pyrimidine nucleobase with a chemical formula of C4H5N3O. Pyrimidine is a heterocyclic aromatic organic compound with a single ring (called a pyrimidine ring) with alternating carbon and nitrogen atoms.