1-Methylcytosine

1-Methylcytosine
Names
	Preferred IUPAC name 4-Amino-1-methylpyrimidin-2(1H)-one
Identifiers
CAS Number	1122-47-0 ;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:39624 ;
ChEMBL	ChEMBL500883;
ChemSpider	71474 ;
MeSH	1-Methylcytosine
PubChem CID	79143;
UNII	1J54NE82RV ;
CompTox Dashboard (EPA)	DTXSID60149949 ;
	InChI InChI=1S/C5H7N3O/c1-8-3-2-4(6)7-5(8)9/h2-3H,1H3,(H2,6,7,9) Key: HWPZZUQOWRWFDB-UHFFFAOYSA-N ; InChI=1S/C5H7N3O/c1-8-3-2-4(6)7-5(8)9/h2-3H,1H3,(H2,6,7,9) Key: HWPZZUQOWRWFDB-UHFFFAOYSA-N;
	SMILES CN1C=CC(=NC1=O)N;
Properties
Chemical formula	C5H7N3O
Molar mass	125.131 g·mol−1
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

1-Methylcytosine (1mC) is a methylated form of the DNA base cytosine. The deoxyribonucleoside it forms is called N¹-methyl-2'-deoxy-pseudocytidine (m¹ΨdC).

In 1-methylcytosine, a methyl group is attached to the 1st atom in the 6-atom ring. This methyl group distinguishes 1-methylcytosine from cytosine. The location distinguishes it from the more (naturally) common 5-methylcytosine.

1mC forms hydrogen bonds differently compared to cytosine because it attaches to the backbone sugar (ribose or deoxyribose) differently: at the C5 position as opposed to cytidine's C1 position, analogous to the difference between pseudouridine and uridine. It pairs with isoguanine in Artificially Expanded Genetic Information System (hachimoji) DNA, replacing the unstable deoxyribonucleoside form of isocytosine.^[1]

History

Miriam Rossi worked on the refinement of the crystallographic structure of 1-methylcytosine.^[2]

It was discovered as a stable replacement for 2'-deoxy-5-methylisocytidine in 2009.^[3]

References

^ Hoshika, Shuichi; et al. (22 February 2019). "Hachimoji DNA and RNA: A genetic system with eight building blocks". Science. 363 (6429): 884–887. Bibcode:2019Sci...363..884H. doi:10.1126/science.aat0971. PMC 6413494. PMID 30792304.
^ Kistenmacher, T. J.; Rossi, M. (1977-12-15). "1-Methylcytosine: a refinement". Acta Crystallographica Section B. 33 (12): 3962–3965. Bibcode:1977AcCrB..33.3962R. doi:10.1107/S0567740877012618. ISSN 0567-7408.
^ Kim, HJ; Leal, NA; Benner, SA (15 May 2009). "2'-deoxy-1-methylpseudocytidine, a stable analog of 2'-deoxy-5-methylisocytidine". Bioorganic & medicinal chemistry. 17 (10): 3728–32. doi:10.1016/j.bmc.2009.03.047. PMID 19394831.

[SCI-20190222-1] Hoshika, Shuichi; et al. (22 February 2019). "Hachimoji DNA and RNA: A genetic system with eight building blocks". Science. 363 (6429): 884–887. Bibcode:2019Sci...363..884H. doi:10.1126/science.aat0971. PMC 6413494. PMID 30792304.

[2] Kistenmacher, T. J.; Rossi, M. (1977-12-15). "1-Methylcytosine: a refinement". Acta Crystallographica Section B. 33 (12): 3962–3965. Bibcode:1977AcCrB..33.3962R. doi:10.1107/S0567740877012618. ISSN 0567-7408.

[3] Kim, HJ; Leal, NA; Benner, SA (15 May 2009). "2'-deoxy-1-methylpseudocytidine, a stable analog of 2'-deoxy-5-methylisocytidine". Bioorganic & medicinal chemistry. 17 (10): 3728–32. doi:10.1016/j.bmc.2009.03.047. PMID 19394831.

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