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 Ls AA9A 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. Ls AA9A has been recombinantly expressed in Escherichia coli with 13 C and 15 N labelling. Here, we present the 1 H, 13 C and 15 N 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 Ls AA9A expressed in E. coli . A few shorter α-helices and β-sheets present in the crystal structure are missing in the NMR prediction and vice versa. Ls AA9A resembles the typical structural elements of LPMOs with a core β-sandwich.