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PDBsum entry 2gps
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References listed in PDB file
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Key reference
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Title
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Is dimerization required for the catalytic activity of bacterial biotin carboxylase?
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Authors
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Y.Shen,
C.Y.Chou,
G.G.Chang,
L.Tong.
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Ref.
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Mol Cell, 2006,
22,
807-818.
[DOI no: ]
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PubMed id
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Abstract
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Acetyl-coenzyme A carboxylases (ACCs) have crucial roles in fatty acid
metabolism. The biotin carboxylase (BC) subunit of Escherichia coli ACC is
believed to be active only as a dimer, although the crystal structure shows that
the active site of each monomer is 25 A from the dimer interface. We report here
biochemical, biophysical, and structural characterizations of BC carrying
single-site mutations in the dimer interface. Our studies demonstrate that two
of the mutants, R19E and E23R, are monomeric in solution but have only a 3-fold
loss in catalytic activity. The crystal structures of the E23R and F363A mutants
show that they can still form the correct dimer at high concentrations. Our data
suggest that dimerization is not an absolute requirement for the catalytic
activity of the E. coli BC subunit, and we propose a new model for the molecular
mechanism of action for BC in multisubunit and multidomain ACCs.
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Figure 2.
Figure 2. Sedimentation Velocity Analytical
Ultracentrifugation Data for the BC Subunit
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Figure 5.
Figure 5. A Model for the Mechanism of Action of BC
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The above figures are
reprinted
by permission from Cell Press:
Mol Cell
(2006,
22,
807-818)
copyright 2006.
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