1.14.99.53 - 1.14.99.53 1.1 A resolution room-temperature X-ray structure and 2.1 A resolution neutron structure, show a putative dioxygen species equatorially bound to the active site copper with elongated density for the dioxygen, most consistent with a Cu(II)-bound peroxide 1.14.99.53 1.55 A resolution structure of N-terminal LPMO10A module reveals deletions of interacting loops that protrude from the core beta-sandwich scaffold in larger LPMO10s 1.14.99.53 analysis of the copper active site 1.14.99.53 calculation of solution structure. Ca2+, Mg2+, Fe3+, Co2+, Zn2+, or Cu2+ ions show binding to an interaction site located between His28 and His114 1.14.99.53 comparative analysis of sequences, solved structures, and homology models from AA9 and AA10 LPMO families.The two LPMO families are highly conserved, structurally they have minimal sequence similarity outside the active site residues 1.14.99.53 crystal structure in the Cu(II)-bound form and photoreduction of the crystalline protein in the x-ray beam, leading to conversion from the initial Cu(II)-oxidized form with two coordinated water molecules, which adopts a trigonal bipyramidal geometry, to a reduced Cu(I) form in a T-shaped geometry with no coordinated water molecules 1.14.99.53 crystallization at pH 3.5. Structure shows shows significant disorder of the active site in the absence of substrate ligand 1.14.99.53 homology modeling and molecular docking, a binding site for the chitin heptamer exists near the histidine brace active site 1.14.99.53 homology modeling reveals the typical central beta-sandwich fold of LPMOs, as well as flexible loops and two stabilizing disulfide bonds. The active site contains the histidine brace, consisting of His1 and His96 coordinating the copper cofactor, and the axial, non-coordinating residue Phe187 1.14.99.53 homology modeling, CbpD is a monomeric tri-modular enzyme with flexible linkers 1.14.99.53 homology modeling. Residues His1 and His61 directly coordinate the basic copper cofactor in T-shaped geometry. The axial, noncoordinating active site residue is Tyr142 1.14.99.53 in presence of Zn2+, to 1.55 A resolution, and in presence of Cu2+, to 1.4 AS resolution 1.14.99.53 molecular dynamics interactions between the LPMO and three different surface topologies of crystalline chitin. Most enzyme-substrate interactions involve the polysaccharide chain that is to be cleaved. Enzyme displays a constrained active site geometry as well as a tunnel connecting the bulk solvent to the copper site, through which only small molecules such as H2O, O2, and H2O2 can diffuse. Rearrangement of Cu-coordinating water molecules is necessary when binding the substrate and also provide a rationale for the experimentally observed C1 oxidative regiospecificity 1.14.99.53 solution-phase structure of apo-LPMO10A and of Cu(I)-LPMO10A. The presence of the metal has minimal effects on the overall protein structure. Large changes in the Cu(II) spin-Hamiltonian parameters are induced upon binding of the substrate. Changes arise from a rearrangement of the copper coordination sphere from a five-coordinate distorted square pyramid to a four-coordinate near-square planar 1.14.99.53 structure of the catalytic domain (residues 37-230, lacking the linker and the CBM2) to 1.08 A resolution. Structure shows the typical LPMO fold with a central beta-sandwich made up by two distorted beta-sheets connected by several loops and helices. The active site is formed by His37 and His144 that coordinate the copper atom in a T-shaped geometry 1.14.99.53 structure of the catalytic domain, residues 37-230, to 1.08 A resolution. The active site in is formed by residues His-37 and His-144 that coordinate the copper atom in a T-shaped geometry 1.14.99.53 structure shows a substrate-binding surface with features similar to known chitin-active LPMOs and the absence of a carbohydrate-binding module 1.14.99.53 structures in the resting state and of a copper(II)-dioxo intermediate complex formed in the absence of substrate reveal pre-bound molecular oxygen adjacent to the active site. A conserved histidine is involved in promoting oxygen activation 1.14.99.53 to 1.2 A resolution. Diffraction resolution and crystal morphology are improved by expression from a glycoengineered strain of Pichia pastoris 1.14.99.53 to 1.3 A resolution 1.14.99.53 to 1.85 A resolution, tri-modular enzyme containing a catalytic family AA10 LPMO module, a family 5 chitin-binding module, and a C-terminal unclassified module which displays tight and specific binding to chitin