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PDBsum entry 1tzc
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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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A novel phosphoglucose isomerase (pgi)/phosphomannose isomerase from the crenarchaeon pyrobaculum aerophilum is a member of the pgi superfamily: structural evidence at 1.16-A resolution.
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Authors
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M.K.Swan,
T.Hansen,
P.Schönheit,
C.Davies.
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Ref.
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J Biol Chem, 2004,
279,
39838-39845.
[DOI no: ]
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PubMed id
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Abstract
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The crystal structure of a dual specificity phosphoglucose isomerase
(PGI)/phosphomannose isomerase from Pyrobaculum aerophilum (PaPGI/PMI) has been
determined in native form at 1.16-A resolution and in complex with the enzyme
inhibitor 5-phosphoarabinonate at 1.45-A resolution. The similarity of its fold,
with the inner core structure of PGIs from eubacterial and eukaryotic sources,
confirms this enzyme as a member of the PGI superfamily. The almost total
conservation of amino acids in the active site, including the glutamate base
catalyst, shows that PaPGI/PMI uses the same catalytic mechanisms for both ring
opening and isomerization for the interconversion of glucose 6-phosphate
(Glc-6-P) to fructose 6-phosphate (Fru-6-P). The lack of structural differences
between native and inhibitor-bound enzymes suggests this activity occurs without
any of the conformational changes that are the hallmark of the well
characterized PGI family. The lack of a suitable second base in the active site
of PaPGI/PMI argues against a PMI mechanism involving a trans-enediol
intermediate. Instead, PMI activity may be the result of additional space in the
active site imparted by a threonine, in place of a glutamine in other PGI
enzymes, which could permit rotation of the C-2-C-3 bond of mannose 6-phosphate.
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Figure 1.
FIG. 1. Fischer projections of the three substrates for
PGI/PMI from P. aerophilum, Glc-6-P, Fru-6-P, and Man-6-P, as
well as the PGI inhibitor used in this study, PAB.
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Figure 6.
FIG. 6. The structure of PGI/PMI from P. aerophilum in
complex with PAB at 1.45-Å resolution. a, a stereo view
showing PAB bound to the active site region. Shown is the active
site from subunit B but the contacts are essentially identical
in subunit A. The electron density shown around the inhibitor in
blue is an unbiased (|F[o]| -|F[c]|) difference map, calculated
from the final coordinates refined in the absence of ligand. The
side chains of those residues surrounding the ligand are shown
in bond form in which carbon, oxygen, and nitrogen are yellow,
red, and blue, respectively, except for His-219 which is colored
orange to indicate it is part of subunit A. PAB is colored with
green bonds. Water molecules are shown as red spheres. Important
contacts are shown as dashed lines. The figure was produced
using PYMOL (40). b, a diagram of the distances (in Å)
between atoms of PAB (colored green) and of amino acids in the
active site (colored black).
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The above figures are
reprinted
by permission from the ASBMB:
J Biol Chem
(2004,
279,
39838-39845)
copyright 2004.
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Secondary reference #1
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Title
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Crystallization and preliminary X-Ray diffraction analysis of phosphoglucose/phosphomannose isomerase from pyrobaculum aerophilum.
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Authors
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M.K.Swan,
T.Hansen,
P.Schönheit,
C.Davies.
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Ref.
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Acta Crystallogr D Biol Crystallogr, 2004,
60,
1481-1483.
[DOI no: ]
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PubMed id
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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
perfect match.
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Figure 2.
Figure 2 Crystals of phosphoglucose isomerase/phosphomannose
isomerase from P. aerophilum grown using the hanging-drop method
with polyethylene glycol 8000 as a precipitant. Their
approximate dimensions are 0.20 × 0.15 × 0.05 mm.
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Figure 3.
Figure 3 A diffraction image collected from crystals of PGI/PMI
from P. aerophilum. The edge of the plate corresponds to 1.7 Å
resolution.
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The above figures are
reproduced from the cited reference
with permission from the IUCr
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