Peptidoglycan glycosyltransferase explained

peptidoglycan glycosyltransferase
Ec Number:	2.4.1.129
Cas Number:	79079-04-2
Go Code:	0008955

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

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,, and .

Notes and References

1. Mesleh MF, Rajaratnam P, Conrad M, Chandrasekaran V, Liu CM, Pandya BA, Hwang YS, Rye PT, Muldoon C, Becker B, Zuegg J, Meutermans W, Moy TI . 6 . Targeting Bacterial Cell Wall Peptidoglycan Synthesis by Inhibition of Glycosyltransferase Activity . Chemical Biology & Drug Design . 87 . 2 . 190–199 . February 2016 . 26358369 . 10.1111/cbdd.12662 .
2. Yuan Y, Barrett D, Zhang Y, Kahne D, Sliz P, Walker S . Crystal structure of a peptidoglycan glycosyltransferase suggests a model for processive glycan chain synthesis . Proceedings of the National Academy of Sciences of the United States of America . 104 . 13 . 5348–5353 . March 2007 . 17360321 . 1817829 . 10.1073/pnas.0701160104 . free . 2007PNAS..104.5348Y .
3. Web site: Information on EC 2.4.1.129 - peptidoglycan glycosyltransferase - BRENDA Enzyme Database . 2022-05-13 . www.brenda-enzymes.org.