The genome of Acremonium sp. DSM 24697 codes for two diglycosidases with different substrate specificity

BÁRBARA NEHER, LAURA S. MAZZAFERRO; GISELA WEIZ ; MICHAEL KOTIK, PETR HALADA, VLADIMIR KREN; JAVIER D. BRECCIA

Montevideo

Encuentro; SiLaBB II - EnReBB VII; 2016

Diglycosidases are endo-β-glucosidases that hydrolyze the heterosidic linkage of diglycoconjugates, splitting off a disaccharide and the corresponding aglycone. The fungusAcremoniumsp. DSM 24697 produces at least two diglycosidases with different substrate specificity. α-Rhamnosyl-β-glucosidase (ARBG)cleaves the disaccharide rutinose from 7 O rutinosylated flavonoids, while ARBGII cleaves rutinose from the3 O rutinosylated flavonoid rutin (Fig 1).The genome of Acremonium sp. DSM 24697 was sequenced using the Illumina technique and assembled to 355 scaffolds (≥0.3 kb; N50, 235 kb) with a total size of ≈27 Mb. ARBG and ARBGII were detected by zymographic assays and a tryptic digestion was performed. The tryptic peptides were used as the probes for a BLAST search against the translated genome. ARBG was predicted not to have introns,a theoretical pI of 5.0 and a molecular mass of 41 kDa, while ARBG II was predicted to have three introns, a theoretical pI of 4.5 and a molecular mass of 80.8 kDa.The cloning and expression of these genes will bring insights into the relationship between sequence and substrate specificity of flavonoid-hydrolyzing enzymes.