1QLG: Crystal Structure Of Phytase With Magnesium From Bacillus Amyloliquefaciens

Phytases hydrolyze phytic acid to less phosphorylated myo-inositol derivatives and inorganic phosphate. A thermostable phytase is of great value in applications for improving phosphate and metal ion availability in animal feed, and thereby reducing phosphate pollution to the environment. Here, we report a new folding architecture of a six-bladed propeller for phosphatase activity revealed by the 2.1 A crystal structures of a novel, thermostable phytase determined in both the partially and fully Ca2+-loaded states. Binding of two calcium ions to high-affinity calcium binding sites results in a dramatic increase in thermostability (by as much as approximately 30 degrees C in melting temperature) by joining loop segments remote in the amino acid sequence. Binding of three additional calcium ions to low-affinity calcium binding sites at the top of the molecule turns on the catalytic activity of the enzyme by converting the highly negatively charged cleft into a favorable environment for the binding of phytate.
PDB ID: 1QLGDownload
MMDB ID: 12826
PDB Deposition Date: 1999/8/31
Updated in MMDB: 2007/10
Experimental Method:
x-ray diffraction
Resolution: 2.2  Å
Source Organism:
Similar Structures:
Biological Unit for 1QLG: monomeric; determined by software (PQS)
Molecular Components in 1QLG
Label Count Molecule
Protein (1 molecule)
Molecule annotation
Chemicals (5 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB