1H, 13C and 15N backbone resonance assignment of the lytic polysaccharide monooxygenase LsAA9A from Lentinus similis

Lytic polysaccharide monooxygenases (LPMOs) are mono-copper binding enzymes involved in the degradation of carbohydrates. The 25 kDa sized LPMO LsAA9A from the basidiomycete Lentinus similis is known to oxidate cellulose and cellooligomers at the C4 position and thus leading to a breakage of the glycosidic bond. LsAA9A has been recombinantly expressed in Escherichia coli with 13C and 15N labelling. Here, we present the 1H, 13C and 15N backbone resonance assignment of the apo form. The secondary structure was predicted using the TALOS-N software and it was overall in agreement with the crystal structure of LsAA9A expressed in E. coli. A few shorter alpha-helices and beta-sheets present in the crystal structure are missing in the NMR prediction and vice versa. LsAA9A resembles the typical structural elements of LPMOs with a core beta-sandwich.