Crystallization and preliminary X-ray crystallographic analysis of a putative feruloyl esterase fromTalaromyces cellulolyticus

Feruloyl esterase (FAE; EC 3.1.1.73) catalyzes the cleavage of the ester bond between ferulic acid and polysaccharides in plant cell walls, and thus holds significant potential for the industrial utilization of biomass saccharification. A feruloyl esterase was identified from the genome database ofTalaromyces cellulolyticus(formerly known asAcremonium cellulolyticus). The gene consists of the catalytic domain and a carbohydrate-binding module connected through a serine/threonine-rich linker region. The recombinant enzyme was prepared, purified and crystallized at 293 K using 0.1 Mimidazole pH 8.0, 0.2 Mcalcium acetate, 14% PEG 8000 as the precipitant. The crystal diffracted to 2.6 Å resolution and the crystal system is primitive orthorhombic, with unit-cell parametersa= 90.9,b= 123.4,c= 135.4 Å. Four molecules are assumed to be present per asymmetric unit, corresponding to a Matthews coefficient of 2.50 Å3 Da−1and a solvent content of 50.88%(v/v).

Crystallization and preliminary X-ray crystallographic analysis of a putative acetylxylan esterase fromTalaromyces cellulolyticus

Acetylxylan esterase (AXE) catalyzes the hydrolytic cleavage of the ester bond between acetic acid and hemicellulose in plant cell walls. A putative AXE gene exhibiting high homology to carbohydrate esterase family 3 was found in the genome database of the fungusTalaromyces cellulolyticus(formerly known asAcremonium cellulolyticus). A truncated form of the protein, the catalytic domain of the enzyme, was prepared and crystallized. The best crystal was obtained at 293 K using 0.17 Mammonium sulfate, 28% PEG 4000, 5%(v/v) glycerol, 0.5%(w/v)n-octyl-β-D-glucoside. X-ray diffraction data were collected to 1.50 Å resolution. The crystal belonged to space groupP41212 orP43212, with unit-cell parametersa= 70.90,b= 70.90,c= 87.09 Å. One enzyme molecule per asymmetric unit gave a crystal volume per protein mass (VM) of 2.62 Å3 Da−1and a solvent content of 53.0%(v/v).