Characterization of a fusarium 2-gene cluster involved in trichothecene C-8 modification.
The Fusarium trichothecenes T-2 toxin and deoxynivalenol (DON) are potent inhibitors of eukaryotic protein synthesis and are a significant agricultural problem. Three coregulated loci are required for T-2 toxin synthesis by Fusarium sporotrichioides. The core-trichothecene gene cluster consists of 12 genes (Tri3-Tri14) while the second locus consists of a single gene (Tri101). The third locus was recently partially described and encodes 1-2 biosynthetic enzymes and a putative regulatory gene. Here, we describe a detailed characterization of this locus. Located adjacent to Tri1 is Tri16, which is required for esterification of the C-8 hydroxyl. A putative regulatory gene, also adjacent to Tri1, is not required for T-2 toxin synthesis. The genomic sequence of Fusarium graminearum (a DON producer) contains a putative functional Tri1 and a nonfunctional Tri16. The presence of the Tri16 pseudogene is consistent with the chemical structure of DON, which has a C-8 keto group rather than the C-8 ester of T-2 toxin.
Brown
Daren W
DW
USDA/ARS, National Center for Agricultural Utilization Research, Peoria, Illinois 61604, USA. browndw@ncaur.usda.gov
Proctor
Robert H
RH
Dyer
Rex B
RB
Plattner
Ronald D
RD
D000217:Acyltransferases / Q000235:genetics; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics; D004951:Esterification; D020224:Expressed Sequence Tags; D005670:Fusarium / Q000201:enzymology / Q000235:genetics*; D017353:Gene Deletion; D008969:Molecular Sequence Data; D012045:Regulatory Sequences, Nucleic Acid; D014255:Trichothecenes / Q000378:metabolism*
D014255:Trichothecenes; D003577:Cytochrome P-450 Enzyme System; D000217:Acyltransferases