Functional and structural characterization of Staphylococcus aureus N‐acetylglucosamine 1‐phosphate uridyltransferase ( GlmU ) reveals a redox‐sensitive acetyltransferase activity
Year: 2025
Type: article
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 KM 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.
Source: Protein Science
DOI: 10.1002/pro.70111
Institution: The University of Adelaide
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,480
OpenAlex ID: W4408922318