 |
PDBsum entry 1fgo
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Oxidoreductase
|
PDB id
|
|
|
|
1fgo
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
Contents |
 |
|
|
|
|
|
|
|
|
|
|
|
|
* Residue conservation analysis
|
|
|
|
|
References listed in PDB file
|
|
|
Key reference
|
|
|
Title
|
|
Structural and functional characterization of second-Coordination sphere mutants of soybean lipoxygenase-1.
|
|
|
Authors
|
|
D.R.Tomchick,
P.Phan,
M.Cymborowski,
W.Minor,
T.R.Holman.
|
|
|
Ref.
|
|
Biochemistry, 2001,
40,
7509-7517.
|
|
|
PubMed id
|
|
|
|
|
|
Abstract
|
|
|
Lipoxygenases are an important class of non-heme iron enzymes that catalyze the
hydroperoxidation of unsaturated fatty acids. The details of the enzymatic
mechanism of lipoxygenases are still not well understood. This study utilizes a
combination of kinetic and structural probes to relate the lipoxygenase
mechanism of action with structural modifications of the iron's second
coordination sphere. The second coordination sphere consists of Gln(495) and
Gln(697), which form a hydrogen bond network between the substrate cavity and
the first coordination sphere (Asn(694)). In this investigation, we compared the
kinetic and structural properties of four mutants (Q495E, Q495A, Q697N, and
Q697E) with those of wild-type soybean lipoxygenase-1 and determined that
changes in the second coordination sphere affected the enzymatic activity by
hydrogen bond rearrangement and substrate positioning through interaction with
Gln(495). The nature of the C-H bond cleavage event remained unchanged, which
demonstrates that the mutations have not affected the mechanism of hydrogen atom
tunneling. The unusual and dramatic inverse solvent isotope effect (SIE)
observed for the Q697E mutant indicated that an Fe(III)-OH(-) is the active site
base. A new transition state model for hydrogen atom abstraction is proposed.
|
|
|
Secondary reference #1
|
|
|
Title
|
|
Crystal structure of soybean lipoxygenase l-1 at 1.4 a resolution.
|
|
|
Authors
|
|
W.Minor,
J.Steczko,
B.Stec,
Z.Otwinowski,
J.T.Bolin,
R.Walter,
B.Axelrod.
|
|
|
Ref.
|
|
Biochemistry, 1996,
35,
10687-10701.
[DOI no: ]
|
|
|
PubMed id
|
|
|
|
|
|
|
|
|
Secondary reference #2
|
|
|
Title
|
|
The structure and function of lipoxygenase.
|
|
|
Authors
|
|
M.J.Nelson,
S.P.Seitz.
|
|
|
Ref.
|
|
Curr Opin Struct Biol, 1994,
4,
878-884.
|
|
|
PubMed id
|
|
|
|
|
|
|
|
|
Secondary reference #3
|
|
|
Title
|
|
Experimental evidence for extensive tunneling of hydrogen in the lipoxygenase reaction: implications for enzyme catalysis
|
|
|
Authors
|
|
T.Jonsson,
M.H.Glickman,
S.Sun,
J.P.Klinman.
|
|
|
Ref.
|
|
j am chem soc, 1996,
118,
10319.
|
|
|
|
Secondary reference #4
|
|
|
Title
|
|
Nature of rate-Limiting steps in the soybean lipoxygenase-1 reaction.
|
|
|
Authors
|
|
M.H.Glickman,
J.P.Klinman.
|
|
|
Ref.
|
|
Biochemistry, 1995,
34,
14077-14092.
[DOI no: ]
|
|
|
PubMed id
|
|
|
|
|
|
|
|
|
Secondary reference #5
|
|
|
Title
|
|
The three-Dimensional structure of an arachidonic acid 15-Lipoxygenase.
|
|
|
Authors
|
|
J.C.Boyington,
B.J.Gaffney,
L.M.Amzel.
|
|
|
Ref.
|
|
Science, 1993,
260,
1482-1486.
[DOI no: ]
|
|
|
PubMed id
|
|
|
|
|
|
|
|
|
Secondary reference #6
|
|
|
Title
|
|
Crystallographic determination of the active site iron and its ligands in soybean lipoxygenase l-1.
|
|
|
Authors
|
|
W.Minor,
J.Steczko,
J.T.Bolin,
Z.Otwinowski,
B.Axelrod.
|
|
|
Ref.
|
|
Biochemistry, 1993,
32,
6320-6323.
[DOI no: ]
|
|
|
PubMed id
|
|
|
|
|
|
|
|
|
Secondary reference #7
|
|
|
Title
|
|
Crystallization and preliminary X-Ray investigation of lipoxygenase 1 from soybeans.
|
|
|
Authors
|
|
J.Steczko,
C.R.Muchmore,
J.L.Smith,
B.Axelrod.
|
|
|
Ref.
|
|
J Biol Chem, 1990,
265,
11352-11354.
|
|
|
PubMed id
|
|
|
|
|
|
|
|
|
|
|
|
|
