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

WEIZ G; NEHER B; MAZZAFERRO L; KOTIK M; HALADA P; KREN V; BRECCIA JD

Montevideo

Simposio; Simposio Latinoamericano de Biocatalisis y Biotransformaciones; 2016

Universidad de la Republica Oriental del Uruguay

Diglycosidases are endo-β-glucosidases that hydrolyze the heterosidic linkage of diglycoconjugates, splitting off a disaccharide and the corresponding aglycone. The fungus Acremonium sp. 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 the 3 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. Figure 1. Structure of flavonoids (A) rutin (quercetin 3-O-(6-O-α-L-rhamnopyranosil-β-D-glucopyranoside) (B) hesperdidin (hesperetin 7-O-(6-O-α-L-rhamnopyranosil-β-D-glucopyranoside)).This work was supported by the National University of La Pampa (UNLPam), the National Council of Scientific and Technical Research (CONICET), and The National Agency for Science and Technology Promotion (ANPCyT) of Argentina. Funding of the bilateral cooperation project 7AMB13AR005 by the Ministry of Education, Youth and Sports (MEYS) of the Czech Republic and the Ministry of Science, Technology and Innovation (MINCYT) of Argentina is acknowledged.