Guanine nucleobase (G)

Guanine is a **purine nucleobase** (chemical formula C₅H₅N₅O) and serves as one of the four principal bases in DNA and RNA, designated by the symbol **G**. In DNA, guanine pairs with cytosine via three hydrogen bonds, contributing to the stability and information encoding of the double helix. It is a planar, aromatic, double-ring structure forming part of the nucleic acid backbone, and also participates in cellular energy metabolism as a component of guanosine triphosphate (GTP). Guanine is susceptible to chemical modifications such as oxidation and alkylation, which can lead to mutagenesis and play roles in disease and therapeutic contexts [1][2][3][4][5][6][7][8].

Other names

GuanineG2-amino-1,7-dihydro-6H-purin-6-onePurine nucleobase G

Alkylation or modification of guanine bases disrupts base pairing, triggering cell cycle arrest or apoptosis; Intercalation between guanine bases disrupts DNA replication and transcription; Platinum agents form adducts with N7 of guanine, causing DNA crosslinking and double-strand breaks