1qlg: Difference between revisions
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==Overview== | ==Overview== | ||
Phytases hydrolyze phytic acid to less phosphorylated myo-inositol | 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== | ==About this Structure== | ||
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[[Category: Bacillus amyloliquefaciens]] | [[Category: Bacillus amyloliquefaciens]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Ha, N | [[Category: Ha, N C.]] | ||
[[Category: Oh, B | [[Category: Oh, B H.]] | ||
[[Category: Shin, S.]] | [[Category: Shin, S.]] | ||
[[Category: CA]] | [[Category: CA]] | ||
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[[Category: thermostable]] | [[Category: thermostable]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:40:59 2008'' | ||
Revision as of 12:41, 21 February 2008
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CRYSTAL STRUCTURE OF PHYTASE WITH MAGNESIUM FROM BACILLUS AMYLOLIQUEFACIENS
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
1QLG is a Single protein structure of sequence from Bacillus amyloliquefaciens with CA and MG as ligands. Active as 3-phytase, with EC number 3.1.3.8 Known structural/functional Site: MG. 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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