Aristolochene synthase. Isolation, characterization, and bacterial expression of a sesquiterpenoid biosynthetic gene (Ari1) from Penicillium roqueforti.
Aristolochene is the likely precursor of the sesquiterpenoid toxins produced by a number of filamentous fungi. One of these, PR-toxin, is produced by Penicillium roqueforti. We report here the isolation of a gene (Ari1) coding for the sesquiterpene cyclase, aristolochene synthase (AS), from P. roqueforti. Nucleotide sequence analysis of genomic and cDNA clones revealed that the Ari1 gene contains two introns. A Protein A/AS fusion enzyme was expressed in Escherichia coli and shown to have sesquiterpene cyclase activity. Analysis of the Protein A/AS fusion enzyme reaction mixtures by TLC and gas chromatography/mass spectrometry identified aristolochene as a major product. The Ari1 gene encodes a polypeptide of molecular weight 39,200. Expression of Ari1 occurs in stationary phase cultures of P. roqueforti and appears to be transcriptionally regulated.
Proctor
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United States Department of Agriculture/Agricultural Research Service, National Center for Agricultural Utilization Research, Peoria, Illinois 61604.
Hohn
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D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D004269:DNA, Bacterial; D004926:Escherichia coli; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D007535:Isomerases / Q000235:genetics*; D008969:Molecular Sequence Data; D010407:Penicillium / Q000201:enzymology* / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D012717:Sesquiterpenes / Q000378:metabolism*
D004269:DNA, Bacterial; D012717:Sesquiterpenes; D007535:Isomerases; C060050:aristolochene synthase