Premium
Crystallization and preliminary X‐ray crystallographic analysis of the small subunit of the heterodimeric laccase POXA3b from Pleurotus ostreatus
Author(s) -
Ferraroni Marta,
Scozzafava Andrea,
Ullah Sana,
Tron Thierry,
Piscitelli Alessandra,
Sannia Giovanni
Publication year - 2014
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.572
H-Index - 37
ISSN - 2053-230X
DOI - 10.1107/s2053230x13032810
Subject(s) - laccase , pleurotus ostreatus , protein subunit , crystallography , chemistry , tetragonal crystal system , crystallization , stereochemistry , biochemistry , enzyme , crystal structure , organic chemistry , mushroom , food science , gene
Laccases are multicopper oxidases of great biotechnological potential. While laccases are generally monomeric glycoproteins, the white‐rot fungus Pleurotus ostreatus produces two closely related heterodimeric isoenzymes composed of a large subunit, homologous to the other fungal laccases, and a small subunit. The sequence of the small subunit does not show significant homology to any other protein or domain of known function and consequently its function is unknown. The highest similarity to proteins of known structure is to a putative enoyl‐CoA hydratase/isomerase from Acinetobacter baumannii , which shows an identity of 27.8%. Diffraction‐quality crystals of the small subunit of the heterodimeric laccase POXA3b (sPOXA3b) from P. ostreatus were obtained using the sitting‐drop vapour‐diffusion method at 294 K from a solution consisting of 1.8 M sodium formate, 0.1 M Tris–HCl pH 8.5. The crystals belonged to the tetragonal space group P 4 1 2 1 2 or P 4 3 2 1 2, with unit‐cell parameters a = 126.6, c = 53.9 Å. The asymmetric unit contains two molecules related by a noncrystallographic twofold axis. A complete data set extending to a maximum resolution of 2.5 Å was collected at 100 K using a wavelength of 1.140 Å.