Bifunctional UDP-N-acetylglucosamine pyrophosphorylase/glucosamine-1-phosphate N-acetyltransferase (IPR005882)

Short name: Bifunctional_GlmU

Overlapping homologous superfamilies

Family relationships



N-Acetylglucosamine-1-PO(4) uridyltransferase (GlmU, EC: is a trimeric bifunctional enzyme that catalyzes the last two sequential reactions in the de novo biosynthetic pathway for UDP-GlcNAc.

The X-ray crystal structure of Escherichia coli GlmU in complex with UDP-GlcNAc and CoA has been determined to 2.1 A resolution and reveals a two-domain architecture that is responsible for these two reactions [PMID: 11329257]. The C-terminal domain is responsible for the CoA-dependent acetylation of Glc-1-PO(4) to GlcNAc-1-PO(4) and displays the longest left-handed parallel beta-helix (LbetaH or LbH) observed to date. The acetyltransferase active site defined by the binding site for CoA makes use of residues from all three subunits and is positioned beneath an open cavity large enough to accommodate the Glc-1-PO(4) acetyl acceptor. The N-terminal domain catalyzes uridyl transfer from UTP to GlcNAc-1-PO(4) to form the final products UDP-GlcNAc and pyrophosphate. This domain is composed of a central seven-stranded beta-sheet surrounded by six alpha-helices in a Rossmann fold-like topology.

GO terms

Biological Process

GO:0000902 cell morphogenesis
GO:0009103 lipopolysaccharide biosynthetic process
GO:0009252 peptidoglycan biosynthetic process

Molecular Function

GO:0003977 UDP-N-acetylglucosamine diphosphorylase activity
GO:0019134 glucosamine-1-phosphate N-acetyltransferase activity
GO:0000287 magnesium ion binding

Cellular Component

GO:0005737 cytoplasm

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.