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PDBsum entry 1o2e
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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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Crystal structures of the free and anisic acid bound triple mutant of phospholipase a2.
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Authors
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K.Sekar,
S.Vaijayanthi mala,
M.Yogavel,
D.Velmurugan,
M.J.Poi,
B.S.Vishwanath,
T.V.Gowda,
A.A.Jeyaprakash,
M.D.Tsai.
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Ref.
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J Mol Biol, 2003,
333,
367-376.
[DOI no: ]
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PubMed id
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Abstract
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Phospholipase A2 catalyses the hydrolysis of the ester bond of
3-sn-phosphoglycerides. Here, we report the crystal structures of the free and
anisic acid-bound triple mutant (K53,56,120M) of bovine pancreatic phospholipase
A2. In the bound triple mutant structure, the small organic molecule p-anisic
acid is found in the active site, and one of the carboxylate oxygen atoms is
coordinated to the functionally important primary calcium ion. The other
carboxylate oxygen atom is hydrogen bonded to the phenolic hydroxyl group of
Tyr69. In addition, the bound anisic acid molecule replaces one of the
functionally important water molecules in the active site. The residues 60-70,
which are in a loop (surface loop), are disordered in most of the bovine
pancreatic phospholipase A2 structures. It is interesting to note that these
residues are ordered in the bound triple mutant structure but are disordered in
the free triple mutant structure. The organic crystallization ingredient
2-methyl-2,4-pentanediol is found near the active site of the free triple mutant
structure. The overall tertiary folding and stereochemical parameters for the
final models of the free and anisic acid-bound triple mutant are virtually
identical.
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Figure 1.
Figure 1. The backbone tracing of the free triple mutant.
The surface loop residues (60-70) and the calcium-binding loop
(27-34) are indicated with the residue numbers at the beginning
as well as at the ends. This Figure was produced using the
program MOLSCRIPT.[44.]
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Figure 4.
Figure 4. Stereo view of the omit electron density map
contoured at the 1.0s level showing the electron density for the
anisic acid molecule in the bound triple mutant structure. In
addition, the only water molecule hydrogen bonded to Nd1 of
His48 is shown and it is 0.49 Å below the plane of the
histidine ring.
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The above figures are
reprinted
by permission from Elsevier:
J Mol Biol
(2003,
333,
367-376)
copyright 2003.
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