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PDBsum entry 3bnc
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Oxidoreductase
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PDB id
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3bnc
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References listed in PDB file
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Key reference
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Title
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Enzyme structure and dynamics affect hydrogen tunneling: the impact of a remote side chain (i553) in soybean lipoxygenase-1.
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Authors
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M.P.Meyer,
D.R.Tomchick,
J.P.Klinman.
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Ref.
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Proc Natl Acad Sci U S A, 2008,
105,
1146-1151.
[DOI no: ]
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PubMed id
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Abstract
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This study examines the impact of a series of mutations at position 553 on the
kinetic and structural properties of soybean lipoxygenase-1 (SLO-1). The
previously uncharacterized mutants reported herein are I553L, I553V, and I553G.
High-resolution x-ray studies of these mutants, together with the earlier
studied I553A, show almost no structural change in relation to the WT-enzyme. By
contrast, a progression in kinetic behavior occurs in which the decrease in the
size of the side chain at position 553 leads to an increased importance of
donor-acceptor distance sampling in the course of the hydrogen transfer process.
These dynamical changes in behavior are interpreted in the context of two
general classes of protein motions, preorganization and reorganization, with the
latter including the distance sampling modes [Klinman JP (2006) Philos Trans R
Soc London Ser B 361:1323-1331; Nagel Z, Klinman JP (2006) Chem Rev
106:3095-3118]. The aggregate data for SLO-1 show how judicious placement of
hydrophobic side chains can influence enzyme catalysis via enhanced
donor-acceptor hydrogenic wave function overlap.
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Figure 4.
Configuration of ligands to the active site iron atom in
I553L. The leucine side chain at position 546 resides one helix
turn away, in the direction of the catalytically active iron
center. The shadow at position 553 traces out the region
occupied by isoleucine in the WT-SLO.
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Figure 5.
Configuration of ligands to the active site iron atom in
I553G. The leucine side chain at position 546 resides one helix
turn away, in the direction of the catalytically active iron
center. The shadow at position 553 traces out the region
occupied by isoleucine in the WT-SLO.
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Secondary reference #1
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Title
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Kinetic studies of oxygen reactivity in soybean lipoxygenase-1.
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Authors
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M.J.Knapp,
J.P.Klinman.
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Ref.
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Biochemistry, 2003,
42,
11466-11475.
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PubMed id
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