http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
sequence and characterization of TRI1, a cytochrome P450 monooxygenase involved in T-2 toxin biosynthesis
Sequence and characterization of TRI one, a cytochrome P-four-five-zero monooxygenase involved in T-two toxin biosynthesis
We report here the sequence and characterization of TRI1 (TRI15), a gene previously defined by two Fusarium sporotrichioides UV mutants, MB1716 and MB1370. Biochemical analysis of MB1716 had indicated that TRI1 was required for the hydroxylation of C8 during T-2 toxin biosynthesis (6). TRI1 cDNA clones were identified during a differential hybridization screen of a cDNA library (A. W. Peplow, A. G. Tag, G. F. Garifullina, and M. N. Beremand, unpublished). Comparative analysis between the genomic and cDNA sequence revealed four introns and a potential 1626 bp ORF that could encode a 542 amino acid protein with homology to a cytochrome P450 monooxygenase. Disruption of TRI1 in F. sporotrichioides NRRL 3299 resulted in an accumulation of 4, 15-diacetoxyscirpenol (DAS). Complementation of the two C8- mutants MB1716 and MB1370, with TRI1 restored T-2 toxin biosynthesis and thus C8 hydroxylation. Analysis of surrounding DNA sequence identified a putative aceytltransferase, designated TRI22, which, like TRI1, is positively regulated by TRI6 (a TRI gene transcriptional activator) and TRI10 (a novel TRI gene regulator). Southern and PCR analysis are consistent with the observation that TRI1 is not located near the core trichothecene gene cluster or near TRI101. The isolation and characterization of TRI1 has provided new insight into T-2 toxin biosynthesis, and supported an expanded model of the trichothecene biosynthetic pathway. Moreover, the characterization of the sequence surrounding TRI1 has identified a potential previously unreported second TRI gene cluster.
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Includes bibliographical references (leaves 50-57).