The Fatty Acid Synthase of the Basidiomycete Omphalotus olearius Is a Single Polypeptide
Fatty acids are essential components of almost all biological membranes. Additionally, they are important in energy storage, as second messengers during signal transduction, and in post-translational protein modification. De novo synthesis of fatty acids is essential for almost all organisms, and entails the iterative elongation of the growing fatty acid chain through a set of reactions conserved in all kingdoms. During our work on the biosynthesis of secondary metabolites, a 450-kDa protein was detected by SDS-PAGE of enriched fractions from mycelial lysates from the basidiomycete Omphalotus olearius. Protein sequencing of this protein band revealed the presence of peptides with homology to both α and β subunits of the ascomycete fatty acid synthase (FAS) family. The FAS encoding gene of O. olearius was sequenced. The positions of its predicted 21 introns were verified. The gene encodes a 3931 amino acids single protein, with an equivalent of the ascomycetous β subunit at the N-terminus and the α subunit at the C-terminus. This is the first report on an FAS protein from a homobasidiomycete and also the first fungal FAS which is comprised of a single polypeptide.
Published in: Zeitschrift für Naturforschung C, 10.1515/znc-2009-3-416, De Gruyter