Purification, crystallization and preliminary crystallographic analysis of the marine -amylase AmyP

AmyP is a raw-starch-degrading -amylase newly identified from a marine metagenome library. It shares low sequence similarity with characterized glycoside hydrolases and was classified into a new subfamily of GH13. In particular, it showed preferential degradation to raw rice starch. Full-length AmyP was cloned and overexpressed in Escherichia coli, then purified and crystallized in the presence of its substrate analogue -cyclodextrin. X-ray diffraction data were collected to a resolution of 2.1 angstrom. The crystal belonged to space group P21212, with unit-cell parameters a = 129.824, b = 215.534, c = 79.699 angstrom, = = = 90 degrees, and was estimated to contain two molecules in one asymmetric unit.