Crystallization and preliminary X‐ray diffraction studies of α‐amylase from the antarctic psychrophile Alteromonas haloplanctis A23

A cold‐active α‐amylase was purified from culture supernatants of the antarctic psychrophile Alteromonas haloplanctis A23 grown at 4 °C. In order to contribute to the understanding of the molecular basis of cold adaptations, crystallographic studies of this cold‐adapted enzyme have been initiated because a three‐dimensional structure of a mesophilic counterpart, pig pancreatic α‐amylase, already exists. α‐Amylase from A. haloplanctis , which shares 53% sequence identity with pig pancreatic α‐amylase, has been crystallized and data to 1.85 Å have been collected. The space group is found to be C222 1 with a = 71.40 Å, b = 138.88 Å, and c = 115.66 Å. Until now, a three‐dimensional structure of a psychrophilic enzyme is lacking.