A preliminary X-ray diffraction study of the laccase from Coriolus zonatus in the native state

The copper-containing enzyme laccase is involved, owing to its oxidase activity, in the biodegradation of lignins-one of the most important bioconversion processes. On the basis of the X-ray diffraction data for the laccase from Coriolus zonatus, the spatial structure of this enzyme is determined with a resolution of 3.2 angstrom. R and R-free are 0.2347 and 0.2976, respectively, and the rms deviations of the bond lengths and the bond angles are 0.009 and 1.547 angstrom, respectively. The three-domain structure of the laccase from Coriolus zonatus is confirmed, where each domain is represented by a protein from the cupredoxin family. The spatial organization of the active center of the protein is established. The mononuclear center contains a copper ion Cu(1) with the atoms of S_Cys453, ND1_His395, and ND1_His458 ligands. The trinuclear center is formed by copper ions Cu(2), Cu(3), and Cu(4), surrounded by ligands of eight nitrogen atoms of the histidines of the first and third domains of the protein His66, His109, His454, His111, His400, His452, His64, and His398. The Cu(1) ion is located at distances of 11.84 and 13.22 angstrom from the Cu(2) and Cu(3) ions, respectively. The distance between the Cu(2) and Cu(3) ions is 5.14 angstrom and the Cu(4)-Cu(2) and Cu(4)-Cu(3) distances are 4.75 and 4.41 angstrom, respectively.