title: Aspergillus fumigatus C-5 sterol desaturases Erg3A and Erg3B: role in sterol biosynthesis and antifungal drug susceptibility.
abstract: Two erg3 genes encoding C-5 sterol desaturase enzymes (Erg3A and Erg3B) in Aspergillus fumigatus were characterized with respect to their nucleotide sequences and null mutant phenotypes. Targeted disruption of the erg3A and erg3B genes and a double gene knockout, erg3A- erg3B-, showed that they are not essential for A. fumigatus viability. Mutant phenotypes clearly showed that Erg3B is a C-5 sterol desaturase, but no apparent role for Erg3A in A. fumigatus ergosterol biosynthesis was found. Susceptibility to amphotericin B, itraconazole, fluconazole, voriconazole, and ketoconazole was not altered in isolates in which erg3A and erg3B were knocked out alone and in combination.
authors.affiliation: Servicio de Micologia, Centro Nacional de Microbiologia, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Alcazar-Fuoli
authors.forename: Emilia
authors.initials: E
authors.lastname: Mellado
authors.forename: Guillermo
authors.initials: G
authors.lastname: Garcia-Effron
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Buitrago
authors.forename: Jordi F
authors.initials: JF
authors.lastname: Lopez
authors.forename: Joan O
authors.initials: JO
authors.lastname: Grimalt
authors.forename: J Manuel
authors.initials: JM
authors.lastname: Cuenca-Estrella
authors.forename: Juan L
authors.initials: JL
authors.lastname: Rodriguez-Tudela
mesh_terms: D001232:Aspergillus fumigatus / Q000737:chemistry / Q000187:drug effects / Q000201:enzymology*; D008826:Microbial Sensitivity Tests; D010088:Oxidoreductases / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D013261:Sterols / Q000032:analysis / Q000096:biosynthesis*
chemical_list: D013261:Sterols; D010088:Oxidoreductases; C039306:sterol delta-5 desaturase