1poo
From Proteopedia
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THERMOSTABLE PHYTASE FROM BACILLUS SP
Overview
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.
About this Structure
1POO is a Single protein structure of sequence from Bacillus amyloliquefaciens with CA as ligand. Active as 3-phytase, with EC number 3.1.3.8 Full crystallographic information is available from OCA.
Reference
Crystal structures of a novel, thermostable phytase in partially and fully calcium-loaded states., Ha NC, Oh BC, Shin S, Kim HJ, Oh TK, Kim YO, Choi KY, Oh BH, Nat Struct Biol. 2000 Feb;7(2):147-53. PMID:10655618
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