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PDBsum entry 1ok4
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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 structure of an archaeal class I aldolase and the evolution of (betaalpha)8 barrel proteins.
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Authors
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E.Lorentzen,
E.Pohl,
P.Zwart,
A.Stark,
R.B.Russell,
T.Knura,
R.Hensel,
B.Siebers.
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Ref.
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J Biol Chem, 2003,
278,
47253-47260.
[DOI no: ]
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PubMed id
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Abstract
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Fructose-1,6-bisphosphate aldolase (FBPA) catalyzes the reversible cleavage of
fructose 1,6-bisphosphate to glyceraldehyde 3-phosphate and dihydroxyacetone
phosphate in the glycolytic pathway. FBPAs from archaeal organisms have recently
been identified and characterized as a divergent family of proteins. Here, we
report the first crystal structure of an archaeal FBPA at 1.9-A resolution. The
structure of this 280-kDa protein complex was determined using single wavelength
anomalous dispersion followed by 10-fold non-crystallographic symmetry averaging
and refined to an R-factor of 14.9% (Rfree 17.9%). The protein forms a dimer of
pentamers, consisting of subunits adopting the ubiquitous (betaalpha)8 barrel
fold. Additionally, a crystal structure of the archaeal FBPA covalently bound to
dihydroxyacetone phosphate was solved at 2.1-A resolution. Comparison of the
active site residues with those of classical FBPAs, which share no significant
sequence identity but display the same overall fold, reveals a common ancestry
between these two families of FBPAs. Structural comparisons, furthermore,
establish an evolutionary link to the triosephosphate isomerases, a superfamily
hitherto considered independent from the superfamily of aldolases.
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Figure 1.
FIG. 1. A, ribbon diagram of the crystal structure of the
Tt-FBPA decamer. Two pentamers face each other with the
N-terminal side of the TIM barrels to form the decamer. Each
monomer in the pentamers is shown in different colors and the
two pentamers in different shadings. The active sites are
located at the C termini of the TIM barrels and point away from
the pentamer-pentamer interface. B, one pentamer is shown in a
view perpendicular to that of A, using the same color coding.
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Figure 3.
FIG. 3. Close-up of the central hole of the pentamer in the
same orientation and color coding as Fig. 1B. The residues
Phe-119, Trp-121, and Lys-122 from each monomer, shown in
ball-and-stick representation, point into the central hole of
the pentamer and perform a continuous stacking.
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The above figures are
reprinted
by permission from the ASBMB:
J Biol Chem
(2003,
278,
47253-47260)
copyright 2003.
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