6TWE

Cu(I) NMR solution structure of the chitin-active lytic polysaccharide monooxygenase BlLPMO10A

Summary for 6TWE

• Entry DOI: 10.2210/pdb6twe/pdb
• Related: 5LW4
• NMR Information: BMRB: 19984
• Descriptor: Putative chitin binding protein, COPPER (I) ION (2 entities in total)
• Functional Keywords: lytic polysaccharide monooxygenase, lpmo, aa10, chitin, oxidoreductase, copper
• Biological source: Bacillus licheniformis DSM 13 = ATCC 14580
• Total number of polymer chains: 1
• Total formula weight: 19258.94

Authors

Courtade, G.,Wimmer, R.,Aachmann, F.L. (deposition date: 2020-01-13, release date: 2020-07-29, Last modification date: 2024-11-13)

Primary citation

Courtade, G.,Ciano, L.,Paradisi, A.,Lindley, P.J.,Forsberg, Z.,Sorlie, M.,Wimmer, R.,Davies, G.J.,Eijsink, V.G.H.,Walton, P.H.,Aachmann, F.L.
Mechanistic basis of substrate-O2coupling within a chitin-active lytic polysaccharide monooxygenase: An integrated NMR/EPR study.
Proc.Natl.Acad.Sci.USA, 117:19178-19189, 2020

PubMed Abstract: Lytic polysaccharide monooxygenases (LPMOs) have a unique ability to activate molecular oxygen for subsequent oxidative cleavage of glycosidic bonds. To provide insight into the mode of action of these industrially important enzymes, we have performed an integrated NMR/electron paramagnetic resonance (EPR) study into the detailed aspects of an AA10 LPMO-substrate interaction. Using NMR spectroscopy, we have elucidated the solution-phase structure of -LPMO10A from , along with solution-phase structural characterization of the Cu(I)-LPMO, showing that the presence of the metal has minimal effects on the overall protein structure. We have, moreover, used paramagnetic relaxation enhancement (PRE) to characterize Cu(II)-LPMO by NMR spectroscopy. In addition, a multifrequency continuous-wave (CW)-EPR and N-HYSCORE spectroscopy study on the uniformly isotope-labeled Cu(II)-bound N-LPMO10A along with its natural abundance isotopologue determined copper spin-Hamiltonian parameters for LPMOs to markedly improved accuracy. The data demonstrate that large changes in the Cu(II) spin-Hamiltonian parameters are induced upon binding of the substrate. These changes arise from a rearrangement of the copper coordination sphere from a five-coordinate distorted square pyramid to one which is four-coordinate near-square planar. There is also a small reduction in metal-ligand covalency and an attendant increase in the d(x-y) character/energy of the singly occupied molecular orbital (SOMO), which we propose from density functional theory (DFT) calculations predisposes the copper active site for the formation of a stable Cu-O intermediate. This switch in orbital character upon addition of chitin provides a basis for understanding the coupling of substrate binding with O activation in chitin-active AA10 LPMOs.

PubMed: 32723819
DOI: 10.1073/pnas.2004277117

Experimental method

SOLUTION NMR