9DQF

Crystal structure of bifunctional GlmU from Staphylococcus aureus NCTC 8325 complexed with acetyl CoA and citrate

Summary for 9DQF

• Entry DOI: 10.2210/pdb9dqf/pdb
• Descriptor: Bifunctional protein GlmU, ACETYL COENZYME *A, CITRIC ACID, ... (4 entities in total)
• Functional Keywords: uridyltransferase, acetyltransferase, transferase
• Biological source: Staphylococcus aureus subsp. aureus NCTC 8325
• Total number of polymer chains: 1
• Total formula weight: 50724.47

Authors

Pederick, J.L.,Bruning, J.B. (deposition date: 2024-09-24, release date: 2025-05-14)

Primary citation

Pederick, J.L.,Kumar, A.,Pukala, T.L.,Bruning, J.B.
Functional and structural characterization of Staphylococcus aureus N-acetylglucosamine 1-phosphate uridyltransferase (GlmU) reveals a redox-sensitive acetyltransferase activity.
Protein Sci., 34:e70111-e70111, 2025

PubMed Abstract: The bifunctional enzyme N-acetylglucosamine 1-phosphate uridyltransferase (GlmU) is a promising antibiotic drug target, as it facilitates the biosynthesis of uridine 5'-diphospho-N-acetylglucosamine, an essential precursor of cell wall constituents. We identified that Staphylococcus aureus GlmU (SaGlmU), which was previously targeted for inhibitor development, possesses a dual-cysteine variation (C379/C404) within the acetyltransferase active site. Enzyme assays performed under reducing and non-reducing conditions revealed that the acetyltransferase activity of SaGlmU is redox-sensitive, displaying ~15-fold lower turnover and ~3-fold higher K value for the acetyl CoA substrate under non-reducing conditions. This sensitivity was absent in a C379A SaGlmU mutant. Analysis of SaGlmU by mass spectrometry, x-ray crystallography, and in silico modeling support that C379 and C404 act as a reversible, redox-sensitive switch by forming a disulfide under non-reducing conditions that impedes acetyl CoA recognition and turnover. Therefore, we recommend that future in vitro screening and characterization of SaGlmU inhibitors consider both reducing and non-reducing conditions.

PubMed: 40143772
DOI: 10.1002/pro.70111

Experimental method

X-RAY DIFFRACTION (1.9 Å)