Identification and functional characterization of the 2-hydroxy fatty N-acyl-Delta3(E)-desaturase from Fusarium graminearum.
Delta3(E)-unsaturated fatty acids are characteristic components of glycosylceramides from some fungi, including also human- and plant-pathogenic species. The function and genetic basis for this unsaturation is unknown. For Fusarium graminearum, which is pathogenic to grasses and cereals, we could show that the level of Delta3-unsaturation of glucosylceramide (GlcCer) was highest at low temperatures and decreased when the fungus was grown above 28 degrees C. With a bioinformatics approach, we identified a new family of polypeptides carrying the histidine box motifs characteristic for membrane-bound desaturases. One of the corresponding genes was functionally characterized as a sphingolipid-Delta3(E)-desaturase. Deletion of the candidate gene in F. graminearum resulted in loss of the Delta3(E)-double bond in the fatty acyl moiety of GlcCer. Heterologous expression of the corresponding cDNA from F. graminearum in the yeast Pichia pastoris led to the formation of Delta3(E)-unsaturated GlcCer.
Zaüner
Simone
S
Biocenter Klein Flottbek and Botanical Garden, University of Hamburg, Ohnhorststr. 18, 22609 Hamburg, Germany.
Zähringer
Ulrich
U
Lindner
Buko
B
Warnecke
Dirk
D
Sperling
Petra
P
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D044943:Fatty Acid Desaturases / Q000378:metabolism*; D005670:Fusarium / Q000201:enzymology*; D017353:Gene Deletion; D015971:Gene Expression Regulation, Enzymologic; D005963:Glucosylceramides / Q000737:chemistry; D006639:Histidine / Q000737:chemistry; D008956:Models, Chemical; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry; D010843:Pichia / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013696:Temperature
D005963:Glucosylceramides; D010455:Peptides; D006639:Histidine; D044943:Fatty Acid Desaturases