In enzymology, an undecaprenyldiphospho-muramoylpentapeptide beta-N-acetylglucosaminyltransferase () is an

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products ...

that catalyzes the

chemical reaction A chemical reaction is a process that leads to the IUPAC nomenclature for organic transformations, chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the pos ...

:UDP-N-acetylglucosamine + Mur₂Ac(oyl-L-Ala-gamma-D-Glu-L-Lys-D-Ala-D-Ala)-diphosphoundecaprenol

\rightleftharpoons

UDP + GlcNAc-(1->4)-Mur₂Ac(oyl-L-Ala-gamma-D-Glu-L-Lys-D-Ala-D-Ala)-diphosphoundecaprenol The 2 substrates of this enzyme are

UDP-N-acetylglucosamine Uridine diphosphate ''N''-acetylglucosamine or UDP-GlcNAc is a nucleotide sugar and a coenzyme in metabolism. It is used by glycosyltransferases to transfer ''N''-acetylglucosamine residues to substrates. D-Glucosamine is made naturally in the f ...

and Mur2Ac(oyl-L-Ala-gamma-D-Glu-L-Lys-D-Ala-D-Ala)-diphosphoundecaprenol, whereas its 2

products Product may refer to: Business * Product (business), an item that serves as a solution to a specific consumer problem. * Product (project management), a deliverable or set of deliverables that contribute to a business solution Mathematics * Produ ...

are UDP and

Lipid II Lipid II is a precursor molecule in the synthesis of the cell wall of bacteria. It is a peptidoglycan, which is amphipathic and named for its bactoprenol hydrocarbon chain, which acts as a lipid anchor, embedding itself in the bacterial cell me ...

. This enzyme belongs to the family of

glycosyltransferase Glycosyltransferases (GTFs, Gtfs) are enzymes (EC 2.4) that establish natural glycosidic linkages. They catalyze the transfer of saccharide moieties from an activated nucleotide sugar (also known as the "glycosyl donor") to a nucleophilic glyco ...

s, specifically the hexosyltransferases. The

systematic name A systematic name is a name given in a systematic way to one unique group, organism, object or chemical substance, out of a specific population or collection. Systematic names are usually part of a nomenclature. A semisystematic name or semitrivial ...

of this enzyme class is UDP-N-acetyl-D-glucosamine:N-acetyl-alpha-D-muramyl(oyl-L-Ala-gamma- D-Glu-L-Lys-D-Ala-D-Ala)-diphosphoundecaprenol beta-1,4-N-acetylglucosaminlytransferase. Another name in common use is MurG transferase. This enzyme participates in

peptidoglycan biosynthesis Peptidoglycan or murein is a unique large macromolecule, a polysaccharide, consisting of sugars and amino acids that forms a mesh-like peptidoglycan layer outside the plasma membrane, the rigid cell wall (murein sacculus) characteristic of most ...

. Variant reactions producing modified cell walls include (not muturally exclusive): * Replacement of lysine residue with meso-diaminopimelate combined with adjacent residues through its L-centre, as it is in Gram-negative and some Gram-positive organisms. * Use of mono-trans,octa-cis-decaprenyl instead of the conventional di-trans,octa-cis-undecaprenol moiety, as found in '' Mycobacterium''.

References

* EC 2.4.1 Enzymes of unknown structure {{2.4-enzyme-stub