Also found in: Dictionary, Thesaurus, Medical, Acronyms, Wikipedia.


guanine (gwäˈnēn), organic base of the purine family. It was reported (1846) to be in the guano of birds; later (1879–84) it was established as one of the major constituents of nucleic acids. The accepted structure of the guanine molecule was proposed in 1875, and the compound was first synthesized in 1900. When combined with the sugar ribose in a glycosidic linkage, guanine forms a derivative called guanosine (a nucleoside), which in turn can be phosphorylated with from one to three phosphoric acid groups, yielding the three nucleotides GMP (guanosine monophosphate), GDP (guanosine diphosphate), and GTP (guanosine triphosphate). Analogous nucleosides and nucleotides are formed from guanine and deoxyribose. The nucleotide derivatives of guanine perform important functions in cellular metabolism. GTP acts as a coenzyme in carbohydrate metabolism and in the biosynthesis of proteins; it can readily donate one of its phosphate groups to adenosine diphosphate (ADP) to form adenosine triphosphate (ATP), an extremely important intermediate in the transfer of chemical energy in living systems. GTP is the source of the guanosine found in RNA and deoxyguanosine triphosphate (dGTP) is the source of the deoxyguanosine in DNA, and thus guanine is intimately involved in the preservation and transfer of genetic information. Guanine is said to account for the iridescence of fish scales and the white, shiny appearance of the skin of many amphibians and reptiles.
The Columbia Electronic Encyclopedia™ Copyright © 2022, Columbia University Press. Licensed from Columbia University Press. All rights reserved.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



2-amino-6-oxypurine. a purine base, widely distributed in animal and plant cells (it is a constituent of nucleic acids and is present in a free state).

It is the main component of the excrements of spiders and birds and was discovered in guano (hence the name). A considerable amount of guanine is present in the scales and skin of fish, reptiles, and amphibians. The calcium compound of guanine gives fish scales their characteristic shine. In mammal organisms, guanine is transformed into xanthine under the action of the enzyme guanase.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.


C5H5ON5 A purine base; occurs naturally as a fundamental component of nucleic acids.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
Sugiyama, "Possible cause of G-C [right arrow] C-G transversion mutation by guanine oxidation product, imidazolone," Chemistry & Biology, vol.
Nagamine, "Role of the amino terminal RHAU-specific motif in the recognition and resolution of guanine quadruplex-RNA by the DEAH-box RNAhelicase RHAU," Nucleic Acids Research, vol.
For 3'-GMP gel, the helical structure is formed by successive stacking of planar hydrogen-bonded guanine tetramers now known as the G-quartets on top of each other.
Kitade, "Cover Picture: Reduction-Responsive Guanine Incorporated into G-Quadruplex-Forming DNA (ChemBioChem 14/2016)," ChemBioChem, vol.
The most frequently observed nucleotide substitutions were a novel variant showing a nucleotide transversion from cytosine (C) to adenine (A) at the position 16173, a nucleotide transition from adenine (A) to guanine (G) at the position of 16175, and a nucleotide substitution from cytosine (C) to guanine (G) at the position of 16176 with the frequencies or 53%, 60%, and 82%, respectively.
Table 1 Lattice parameters for Flabellina iodinea crystals and known polymorphs of guanine Purified from Purified from Source F.
In place of guanine, RNA could have relied on a surrogate -- inosine.
Paradoxically, the guanine squares don't reflect light on their own - they're transparent.
Due to increased stability of its enol form, it is possible that 5-bromo uracil may pair with guanine instead of with adenine.
Hypoxanthine guanine phosphoribosyltransferase (HPRT) mutations in the Asian population.
VAL-083 (dianhydrogalactitol) is a first-in-class, DNA-targeting agent that introduces interstrand DNA cross-links at the N7-position of guanine leading to DNA double-strand breaks and cancer cell death.

Full browser ?