5-Methylcytosine

5-Methylcytosine

Names
Preferred IUPAC name 4-Amino-5-methylpyrimidin-2(1H)-one
Identifiers
CAS Number	554-01-8 Y
3D model (JSmol)	Interactive image Interactive image
3DMet	B00435
Beilstein Reference	120387
ChEBI	CHEBI:27551 Y
ChemSpider	58551 Y
ECHA InfoCard	100.008.236
EC Number	209-058-3
KEGG	C02376 Y
MeSH	5-Methylcytosine
PubChem CID	65040
UNII	6R795CQT4H Y
CompTox Dashboard (EPA)	DTXSID50203948
InChI InChI=1S/C5H7N3O/c1-3-2-7-5(9)8-4(3)6/h2H,1H3,(H3,6,7,8,9) Y Key: LRSASMSXMSNRBT-UHFFFAOYSA-N Y InChI=1/C5H7N3O/c1-3-2-7-5(9)8-4(3)6/h2H,1H3,(H3,6,7,8,9) Key: LRSASMSXMSNRBT-UHFFFAOYAO
SMILES O=C1/N=C\C(=C(\N)N1)C Cc1cnc(=O)[nH]c1N
Properties
Chemical formula	C5H7N3O
Molar mass	125.131 g·mol−1
Hazards
GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H317, H319
Precautionary statements	P261, P264, P272, P280, P302+P352, P305+P351+P338, P321, P333+P313, P337+P313, P363, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

5-Methylcytosine is a methylated form of the DNA base cytosine (C) that regulates gene transcription and takes several other biological roles.^[1] When cytosine is methylated, the DNA maintains the same sequence, but the expression of methylated genes can be altered (the study of this is part of the field of epigenetics). 5-Methylcytosine is incorporated in the nucleoside 5-methylcytidine.

In 5-methylcytosine, a methyl group is attached to the 5th atom in the 6-atom ring, counting counterclockwise from the NH-bonded nitrogen at the six o'clock position. This methyl group distinguishes 5-methylcytosine from cytosine.