Deoxyguanosine monophosphate Definition and Examples

Table of Contents

Definition

noun
plural: deoxyguanosine monophosphates
(biochemistry) A nucleotide composed of guanine, deoxyribose and a phosphate group, with a chemical formula: C₁₀H₁₄N₅O₇P

Details

Overview

A nucleotide is an organic compound made up of three subunits: a nucleobase, a five-carbon sugar, and a phosphate group. The sugar component may either be ribose or deoxyribose. The ribose is the sugar component of the nucleotides that make up RNA. The deoxyribose is the sugar component of DNA. Nucleotides are the monomeric units of nucleic acids. Each phosphate group connects the sugar rings of two adjacent nucleotide monomers. The phosphate groups and the sugar moieties form the backbone of a nucleic acid. The directionality of the chain runs from 5′-end to 3′-end. In DNA, the orientation of the two strands is in opposite directions. This is to allow complementary base pairing between nucleobase constituents. A nucleotide is, thus, a nucleoside with a phosphate group. Depending on the number of phosphate groups attached to the sugar moiety, it may be called nucleoside monophosphate (if with only one phosphate group), nucleoside diphosphate (with two phosphate groups), or nucleoside triphosphate (when with three phosphate groups). Depending on the pentose sugar component, a nucleoside may be a ribonucleoside or a deoxyribonucleoside. A ribonucleoside is a nucleoside with a ribose sugar component. (Depending on the nucleobase component, the ribonucleoside may be adenosine, guanosine, cytidine, uridine, or 5-methyluridine). A deoxyribonucleoside is a nucleoside with a deoxyribose sugar. Depending on the nucleobase component, a deoxyribonucleoside may be deoxyadenosine, deoxyguanosine, deoxycytidine, thymidine, or deoxyuridine. Also, depending on the nucleobase component, the nucleosides may be grouped into either the “double-ringed” purine or the “single-ringed” pyrimidine.
Deoxyguanosine monophosphate is a purine nucleotide composed of guanine, deoxyribose and a phosphate group, with a chemical formula: C₁₀H₁₄N₅O₇P

Characteristics

Deoxyguanosine monophosphate (dGMP) is a nucleoside phosphate in being comprised of a deoxyribonucleoside and one phosphate group. This means that it has a deoxyribose as its sugar constituent with one phosphate group attached. Its nucleoside contains a purine base, i.e. a guanine attached to the deoxyribose sugar. It has only one phosphate group attached to the nucleoside. Its conjugate acid form is deoxyguanylic acid whereas its conjugate base form is deoxyguanylate.

dGMP vs GMP

Guanosine monophosphate (GMP) is a nucleotide composed of guanine, ribose and a phosphate group. It has a chemical formula of C₁₀H₁₄N₅O₈P. It differs from dGMP (chemical formula: C₁₀H₁₄N₅O₇P) in terms of the sugar component. dGMP, instead of having a hydroxyl group on the 2′ carbon of the sugar component as it is in GMP, has it reduced to a hydrogen atom (thus, deoxy- in its name). dGMP is one of the monomeric units that constitute DNA whereas GMP is one of the monomeric units that make up RNA.

Common biological reactions

dGMP forms when GMP is reduced. GMP can come from the degradation of GTP (guanosine triphosphate) and GDP (guanosine diphosphate) via hydrolysis, and then reducing the hydroxyl group of the ribose to hydrogen ion. GMP may also be derived from dietary sources (particularly, RNA-rich food). Or, it may be synthesized de novo, starting with D-ribose 5′-phosphate from the pentose phosphate pathway. By the de novo synthesis pathway, inosine monophosphate (IMP) from amino acids, phosphoribosylpyrophosphate (PRPP), and folate is oxidized to xanthosine monophosphate (XMP) using NAD.

Biological functions

dGMP may serve as one of the monomer nucleotides in DNA when it is phosphorylated with two more phosphate groups, thus becoming dGTP (deoxyguanosine triphosphate). In DNA, dGTP complementary base pairs with deoxycytidine triphosphate (dCTP).