 |
PDBsum entry 1tpc
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Isomerase(intramolecular oxidoreductase)
|
PDB id
|
|
|
|
1tpc
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
Contents |
 |
|
|
|
|
|
|
|
|
|
|
|
|
* Residue conservation analysis
|
|
|
|
|
References listed in PDB file
|
|
|
Key reference
|
|
|
Title
|
|
The structural basis for pseudoreversion of the e165d lesion by the secondary s96p mutation in triosephosphate isomerase depends on the positions of active site water molecules.
|
|
|
Authors
|
|
E.A.Komives,
J.C.Lougheed,
K.Liu,
S.Sugio,
Z.Zhang,
G.A.Petsko,
D.Ringe.
|
|
|
Ref.
|
|
Biochemistry, 1995,
34,
13612-13621.
[DOI no: ]
|
|
|
PubMed id
|
|
|
|
|
|
|
|
|
Abstract
|
|
|
The structural basis for the improvement in catalytic efficiency of the mutant
E165D chicken triosephosphate isomerase by the secondary mutation, S96P, has
been analyzed using a combination of X-ray crystallography and Fourier transform
infrared spectroscopy. All X-ray structures were of the complex of
phosphoglycolohydroxamate (PGH), an intermediate analog, with the isomerase, and
each was solved to a resolution of 1.9 A. Comparison of the structure of the
double mutant, E165D.S96P, with that of the single mutant, E165D, as well as
with the wild-type isomerase shows only insignificant differences in the
positions of the side chains in all of the mutants when compared with the
wild-type isomerase, except that in both the E165D and E165D.S96P mutants, the
aspartate side chain was approximately 0.7 A further away from the substrate
analog than the glutamate side chain. Significant differences were observed in
the crystal structure of the E165D.S96P double mutant in the positions of
ordered water molecules bound at the active site. The loss of two water
molecules located near the side chain at position 165 was observed in isomerases
containing the S96P mutation. The resulting increase in hydrophobicity of the
pocket probably causes an increase in the pKa of the catalytic base, D165,
thereby improving its basicity. A new ordered water molecule was observed
underneath the bound PGH in the E165D.S96P structure, which likely decreases the
pKa's of the substrate protons, thereby increasing their acidity. An enzyme
derived carbonyl stretch at 1746 cm-1 that is only observed in the IR spectrum
of the E165D.S96P double mutant isomerase with bound substrates has been
assigned to a stable ground state protonated D165-enediol(ate) intermediate
complex. Thus, the gain in activity resulting from the S96P second site change
probably results from a combination of improving the basicity of the enzyme,
improving the acidity of the substrate protons, and stabilization of a reaction
intermediate. All three of these effects seem to be caused by changes in bound
water molecules.
|
|
|
Secondary reference #1
|
|
|
Title
|
|
Offset of a catalytic lesion (glu165asp) of triosephosphate isomerase by bound waters soluble
|
|
|
Authors
|
|
Z.Zhang,
E.A.Komives,
S.Sugio,
K.D.Liu,
J.R.Knowles,
G.A.Petsko,
D.Ringe.
|
|
|
Ref.
|
|
TO BE PUBLISHED ...
|
|
|
|
Secondary reference #2
|
|
|
Title
|
|
Triosephosphate isomerase drinks water to keep healthy
|
|
|
Authors
|
|
Z.Zhang,
S.Sugio,
A.M.Stock,
E.A.Komives,
K.D.Liu,
N.Narayana,
Ng.H.Huong,
J.R.Knowles,
G.A.Petsko,
D.Ringe.
|
|
|
Ref.
|
|
TO BE PUBLISHED ...
|
|
|
|
Secondary reference #3
|
|
|
Title
|
|
The structural basis for pseudoreversion of the e165d lesion by the secondary s96p mutation in triosephosphate isomerase depends on the positions of active site water molecules.
|
|
|
Authors
|
|
E.A.Komives,
J.C.Lougheed,
K.Liu,
S.Sugio,
Z.Zhang,
G.A.Petsko,
D.Ringe.
|
|
|
Ref.
|
|
Biochemistry, 1995,
34,
13612-13621.
[DOI no: ]
|
|
|
PubMed id
|
|
|
|
|
Note In the PDB file this reference is
annotated as "TO BE PUBLISHED".
The citation details given above were identified by an automated
search of PubMed on title and author
names, giving a
percentage match of
88%.
|
|
|
|
|
|
|
Secondary reference #4
|
|
|
Title
|
|
S96p change is the second-Site suppressor for the h95n sluggish mutant isomerase
|
|
|
Authors
|
|
Z.Zhang,
S.Sugio,
E.A.Komives,
K.D.Liu,
A.M.Stock,
N.Narayana,
Ng.H.Xuong,
J.R.Knowles,
G.A.Petsko,
D.Ringe.
|
|
|
Ref.
|
|
TO BE PUBLISHED ...
|
|
|
|
Secondary reference #5
|
|
|
Title
|
|
How can a catalytic lesion be offset? the energetics of two pseudorevertant triosephosphate isomerases.
|
|
|
Authors
|
|
S.C.Blacklow,
J.R.Knowles.
|
|
|
Ref.
|
|
Biochemistry, 1990,
29,
4099-4108.
[DOI no: ]
|
|
|
PubMed id
|
|
|
|
|
|
|
|
|
|
|
|
|
