Abstract
Industrial demand for active biocatalysts with desirable biochemical properties is constantly increasing and the discovery and characterization of novel esterases is potentially useful for industrial processes. Here, X-ray crystallographic studies of an (R)-specific SGNH arylesterase (Sm23) from Sinorhizobium meliloti 1021 are reported. The recombinant protein was expressed in Escherichia coli with a His tag and purified to homogeneity. Sm23 was crystallized using 0.2 M magnesium formate as a precipitant and X-ray diffraction data were collected to a resolution of 2.2 Å with an R(merge) of 6.9%. The crystals of SM23 belonged to the I-centred tetragonal space group I4(1)22, with unit-cell parameters a = b = 126.6, c = 190.9 Å. A molecular-replacement solution was obtained using the crystal structure of arylesterase from Mycobacterium smegmatis as a template.