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PDBsum entry 1skb
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Contents |
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* Residue conservation analysis
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References listed in PDB file
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Key reference
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Title
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Crystallographic snapshots of aspergillus fumigatus phytase, Revealing its enzymatic dynamics.
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Authors
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Q.Liu,
Q.Huang,
X.G.Lei,
Q.Hao.
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Ref.
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Structure, 2004,
12,
1575-1583.
[DOI no: ]
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PubMed id
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Abstract
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Understanding of the atomic movements involved in an enzymatic reaction needs
structural information on the active and inactive native enzyme molecules and on
the enzyme-substrate, enzyme-intermediate, and enzyme-product(s) complexes. By
using the X-ray crystallographic method, four crystal structures of Aspergillus
fumigatus phytase were obtained at resolution higher than 1.7 A. The
pH-dependent catalytic activity of A. fumigatus phytase was linked to three
water molecules that may prevent the substrate from binding and thus block
nucleophilic attack of the catalytic imidazole nitrogen. Comparison of various
structures also identified the water molecule that attacks the phosphamide bond
during the hydrolysis process, and established the hydrolysis pathway of the
intermediate. Additionally, two reaction product phosphates were observed at the
active site, suggesting a possible product release pathway after hydrolysis of
the intermediate. These results can help explain the catalytic mechanism
throughout the whole acid phosphatase family, as all key residues are conserved.
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Figure 7.
Figure 7. The Release Pathway of Phosphate IonsPO4 501 is
the phosphate near the catalytic residue and PO4 502 is the
phosphate with hydrogen bonding to five water molecules. This
figure was prepared with Ligplot (Wallace et al., 1995).
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The above figure is
reprinted
by permission from Cell Press:
Structure
(2004,
12,
1575-1583)
copyright 2004.
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