deoksiguanosine

Deoksiguanosine, commonly called deoxyguanosine, is a deoxyribonucleoside formed by the guanine nucleobase linked to a 2'-deoxyribose sugar via a beta-N9 glycosidic bond. It is one of the four nucleosides that constitute DNA, with guanine pairing with cytosine in base pairing during replication and transcription in the DNA duplex. In its triphosphate form, dGTP, it serves as a substrate for DNA polymerases during DNA synthesis and repair.

In cells, deoxyguanosine can be phosphorylated to dGMP by deoxynucleoside kinases, such as deoxyguanosine kinase, and then further to dGDP and dGTP. These deoxynucleotides provide the building blocks for DNA replication and are involved in maintaining the proper deoxynucleotide pool balance. Deoxyguanosine can also be degraded or salvaged through purine metabolism. Purine nucleoside phosphorylase can convert deoxyguanosine to guanine and deoxyribose-1-phosphate, with guanine entering the purine catabolic pathway toward uric acid. Alternatively, guanine and deoxyguanosine can be recycled via purine salvage pathways that regenerate GMP and dGTP, respectively, through the action of salvage enzymes and kinases.

Biological relevance includes the role of dGTP pool balance in genome stability and the functioning of DNA synthesis and repair processes. Abnormalities in purine metabolism or disruptions of nucleotide pools can influence mutagenesis and are of interest in contexts such as cancer biology and antiviral or anticancer therapies that target nucleotide metabolism. See also deoxyribonucleosides and purine metabolism.