Sesquiterpene Cyclases from the Basidiomycete Cerrena unicolor

Hundreds of terpenoids have been isolated from Basidiomycota, among them are volatile mono- and sesquiterpenes with amazing sensory qualities, representing a promising alternative to essential oils endangered plant species. Sesquiterpene synthases (STS) appear be an abundant class enzymes in these fungi. The basidiomycete Cerrena unicolor, known sesquiterpene producer, was silico screened for cyclases via homology Basic Local Alignment Search Tool searches. Cyclase genes identified were cloned heterologously expressed Escherichia coli Bl21 using pCOLD I as the expression vector. Ten successfully produced purified, their identity confirmed amino acid sequencing tryptic peptides by nano-liquid chromatography-high resolution-electrospray ionization-tandem mass spectrometry. Gas chromatography/mass spectrometry analysis applied characterize according formation hydrocarbons oxidized terpenoids. Bioinformatic characterization phylogenetic determination allowed classification diverse fungal enzymes. A representative single multi-product STS, respectively, further analyzed dependency divalent metal cations cofactor catalytic activity.