title: Genetic and structural validation of Aspergillus fumigatus N-acetylphosphoglucosamine mutase as an antifungal target.
abstract: Aspergillus fumigatus is the causative agent of IA (invasive aspergillosis) in immunocompromised patients. It possesses a cell wall composed of chitin, glucan and galactomannan, polymeric carbohydrates synthesized by processive glycosyltransferases from intracellular sugar nucleotide donors. Here we demonstrate that A. fumigatus possesses an active AfAGM1 (A. fumigatus N-acetylphosphoglucosamine mutase), a key enzyme in the biosynthesis of UDP (uridine diphosphate)-GlcNAc (N-acetylglucosamine), the nucleotide sugar donor for chitin synthesis. A conditional agm1 mutant revealed the gene to be essential. Reduced expression of agm1 resulted in retarded cell growth and altered cell wall ultrastructure and composition. The crystal structure of AfAGM1 revealed an amino acid change in the active site compared with the human enzyme, which could be exploitable in the design of selective inhibitors. AfAGM1 inhibitors were discovered by high-throughput screening, inhibiting the enzyme with IC50s in the low μM range. Together, these data provide a platform for the future development of AfAGM1 inhibitors with antifungal activity.
authors.affiliation: *Division of Molecular Microbiology, University of Dundee, DD1 5EH, Scotland, U.K.
authors.forename: Wenxia
authors.initials: W
authors.lastname: Fang
authors.affiliation: †State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, People's Republic of China.
authors.forename: Ting
authors.initials: T
authors.lastname: Du
authors.affiliation: *Division of Molecular Microbiology, University of Dundee, DD1 5EH, Scotland, U.K.
authors.forename: Olawale G
authors.initials: OG
authors.lastname: Raimi
authors.affiliation: *Division of Molecular Microbiology, University of Dundee, DD1 5EH, Scotland, U.K.
authors.forename: Ramón
authors.initials: R
authors.lastname: Hurtado-Guerrero
authors.affiliation: ‡Division of Biological Chemistry and Drug Discovery, University of Dundee, DD1 5EH, Scotland, U.K.
authors.forename: Karina
authors.initials: K
authors.lastname: Mariño
authors.affiliation: §The College of Life Sciences Cloning Team, College of Life Sciences, University of Dundee, DD1 5EH, Scotland, U.K.
authors.forename: Adel F M
authors.initials: AF
authors.lastname: Ibrahim
authors.affiliation: *Division of Molecular Microbiology, University of Dundee, DD1 5EH, Scotland, U.K.
authors.forename: Osama
authors.initials: O
authors.lastname: Albarbarawi
authors.affiliation: ‡Division of Biological Chemistry and Drug Discovery, University of Dundee, DD1 5EH, Scotland, U.K.
authors.forename: Michael A J
authors.initials: MA
authors.lastname: Ferguson
authors.affiliation: †State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, People's Republic of China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Jin
authors.affiliation: *Division of Molecular Microbiology, University of Dundee, DD1 5EH, Scotland, U.K.
authors.forename: Daan M F
authors.initials: DM
authors.lastname: Van Aalten
mesh_terms: D000935:Antifungal Agents / Q000737:chemistry; D001232:Aspergillus fumigatus / Q000201:enzymology* / Q000648:ultrastructure; D020134:Catalytic Domain; D002473:Cell Wall / Q000201:enzymology; D018360:Crystallography, X-Ray; D005656:Fungal Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000235:genetics; D006801:Humans; D020128:Inhibitory Concentration 50; D007700:Kinetics; D008274:Magnesium; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability; D008958:Models, Molecular; D017875:Phosphotransferases (Phosphomutases) / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000235:genetics; D017433:Protein Structure, Secondary
chemical_list: D000935:Antifungal Agents; D005656:Fungal Proteins; D017875:Phosphotransferases (Phosphomutases); D008274:Magnesium