Peptidoglycan glycosyltransferase

Peptidoglycan glycosyltransferase (EC 2.4.1.129) is an enzyme used in the biosynthesis of peptidoglycan. It transfers a disaccharide-peptide from a donor substrate to synthesize a glycan chain.^[1]

peptidoglycan glycosyltransferase
Identifiers
EC no.	2.4.1.129
CAS no.	79079-04-2
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Gene Ontology	AmiGO / QuickGO
Search PMC articles PubMed articles NCBI proteins

This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is undecaprenyldiphospho-(N-acetyl-D-glucosaminyl-(1->4)-(N-acetyl-D-mu ramoylpentapeptide):undecaprenyldiphospho-(N-acetyl-D-glucosaminyl-( 1->4)-N-acetyl-D-muramoylpentapeptide) disaccharidetransferase. Other names in common use include PG-II, bactoprenyldiphospho-N-acetylmuramoyl-(N-acetyl-D-glucosaminyl)-, pentapeptide:peptidoglycan, N-acetylmuramoyl-N-acetyl-D-glucosaminyltransferase, penicillin binding protein (3 or 1B), and peptidoglycan transglycosylase.

Function

Peptidoglycan glycosyltransferase couples Lipid II subunits to synthesize the peptidoglycan chains. Transpeptidases crosslink the carbohydrate chains to provide the framework for the cell wall.^[2]

It catalyzes the chemical reaction

[GlcNAc-(1->4)-Mur₂Ac(oyl-L-Ala-gamma-D-Glu-L-Lys-D-Ala-D-Ala)]n-diphosphoundecaprenol + GlcNAc-(1->4)-Mur₂Ac(oyl-L-Ala-gamma-D-Glu-L-Lys-D-Ala-D-Ala)-diphosphoundecaprenol

⇌

[GlcNAc-(1->4)-Mur₂Ac(oyl-L-Ala-gamma-D-Glu-L-Lys-D-Ala-D-Ala)]n⁺1- diphosphoundecaprenol + undecaprenyl diphosphate

The 2 substrates of this enzyme are

• [GlcNAc-(1->4)-Mur2Ac(oyl-L-Ala-gamma-D-Glu-L-Lys-D-Ala-D-Ala)]n-diphosphoundecaprenol,
• GlcNAc-(1->4)-Mur2Ac(oyl-L-Ala-gamma-D-Glu-L-Lys-D-Ala-D-Ala)-diphosphoundecaprenol,

whereas its 2 products are

• [GlcNAc-(1->4)-Mur2Ac(oyl-L-Ala-gamma-D-Glu-L-Lys-D-Ala-D-Ala)]n+1-diphosphoundecaprenol, and
• undecaprenyl diphosphate.^[3]

Structural studies

As of late 2007, 3 structures have been solved for this class of enzymes, with PDB accession codes 2BG1, 2UWX, and 2UWY.