Discovery of fungal oligosaccharide-oxidising flavo-enzymes with previously unknown substrates, redox-activity profiles and interplay with LPMOs

• DOI: 10.1038/s41467-021-22372-0
• Publication Date: 2021-04-09T10:04:15Z
• Authors: Majid Haddad Momeni; Folmer Fredslund; Bastien Bissaro; Olanrewaju Raji; Thu V. Vuong; Sebastian Meier; Tine Sofie Nielsen; Vincent Lombard; Bruno Guigliarelli; Frédéric Biaso; Mireille Haon; Sacha Grisel; Bernard Henrissat; Ditte Hededam Welner; Emma R. Master; Jean-Guy Berrin; Maher Abou Hachem
• Keywords: Oligosaccharide

Oxidative plant cell-wall processing enzymes are of great importance in biology and biotechnology. Yet, our insight into the functional interplay amongst such oxidative remains limited. Here, a phylogenetic analysis auxiliary activity 7 family (AA7), currently harbouring oligosaccharide flavo-oxidases, reveals striking abundance AA7-genes phytopathogenic fungi Oomycetes. Expression five fungal enzymes, including three from unexplored clades, expands AA7-substrate range unveils cellooligosaccharide dehydrogenase activity, previously unknown within AA7. Sequence structural analyses identify unique signatures distinguishing strict clade canonical AA7 oxidases. The discovered directly is able to transfer electrons an AA9 lytic polysaccharide monooxygenase (LPMO) fuel cellulose degradation by LPMOs without exogenous reductants. expansion redox-profiles substrate highlights diversity sets stage for harnessing dehydrogenases fine-tune LPMO biotechnological conversion feedstocks.