Guanine (G)

Guanine is one of the four main nitrogenous bases found in DNA and RNA, alongside adenine, cytosine, and thymine (or uracil in RNA)[1][2][3]. It is a purine derivative with a fused pyrimidine-imidazole ring system[1][8]. In double-stranded DNA, guanine pairs specifically with cytosine via three hydrogen bonds—this strong pairing contributes to the stability of regions rich in CG content[2][4][7]. Guanine’s primary biological function is as a building block of nucleic acids; its sequence within DNA encodes genetic information essential for all cellular processes[3][5][6]. Guanine itself does not act as an enzyme, receptor, transporter, or other classical therapeutic target. Instead, it serves as an informational molecule within the genome. While chemical modifications or mutations involving guanine can play roles in disease processes such as cancer (e.g., through mutagenesis), "guanine" alone is not considered a druggable molecular target nor does it have interacting drugs specific to it[1][3]. Because "guanine" refers to a nucleotide base rather than a protein or functional macromolecule typically targeted by therapeutics—and because there are no drugs that directly bind guanine for therapeutic effect—the entry "Guanine in DNA" should be marked as incorrect for most structured drug-target databases. > **Note:** If you are seeking information on enzymes that interact with guanine-containing sequences (such as DNA polymerases) or proteins that recognize specific guanine motifs (like transcription factors), those would be separate entries. Here we focus strictly on the nucleotide base itself. **Summary:** Guanine is an essential purine nucleobase found in both DNA and RNA; it encodes genetic information but does not serve as a conventional therapeutic target[1][2].

Other names

2-amino-6-oxypurineGuaG