Introduction
Auxiliary Activities (AA) cover redox enzymes that act in conjunction with CAZymes.
Since its inception, the carbohydrate-active enzymes database (CAZy ; www.cazy.org) has described the families of enzymes that cleave or build complex carbohydrates, namely the glycoside hydrolases (GH), the polysaccharide lyases (PL), the carbohydrate esterases (CE), the glycosyltransferases (GT) and their appended non-catalytic carbohydrate-binding modules (CBM). The recent discovery that members of families CBM33 and family GH61 are in fact lytic polysaccharide mono-oxygenases (LPMO), demanded a reclassification of these families into a suitable category. Because lignin is invariably found together with polysaccharides in the plant cell wall and because lignin fragments are likely to act in concert with (LPMO)s, we have decided to join the families of lignin degradation enzymes to the LPMO families and launch a new CAZy class that we name "auxiliary activities" in order to accommodate a range of enzyme mechanisms and substrates [1]<pubmed>.
The AA class presently groups 9 families of ligninolytic enzymes and 7 families of lytic polysaccharide mono-oxygenases. Lignin breakdown enzymes may not act on carbohydrates, but because lignin is invariably and intimately associated with carbohydrates in the plant cell wall, the lignolytic enzymes do cooperate with classical polysaccharide depolymerases. This section of the CAZy database presents a classification of these enzymes in families and subfamilies based on amino acid sequence similarities, intended to reflect structural features and to facilitate genome annotation.
AA Family Number