Expression at 279 K, purification, crystallization and preliminary X‐ray crystallographic analysis of a novel cold‐active β‐1,4‐D‐mannanase from the Antarctic springtail Cryptopygus antarcticus

The CaMan gene product from Cryptopygus antarcticus , which belongs to the glycoside hydrolase family 5 type β‐1,4‐D‐mannanases, has been crystallized using a precipitant solution consisting of 0.1  M Tris–HCl pH 8.5, 25%( w / v ) polyethylene glycol 3350 by the microbatch crystallization method at 295 K. The Ca Man protein crystal belonged to space group P 2 1 2 1 2 1 , with unit‐cell parameters a = 73.40, b  = 83.81, c = 163.55 Å. Assuming the presence of two molecules in the asymmetric unit, the solvent content was estimated to be about 61.29%. Ca Man–mannopentaose (M5) complex crystals that were isomorphous to the Ca Man crystals were obtained using the same mother liquor containing 1 m M M5.