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PDBsum entry 4f0x
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References listed in PDB file
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Key reference
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Title
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Structural asymmetry and disulfide bridges among subunits modulate the activity of human malonyl-Coa decarboxylase.
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Authors
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D.Aparicio,
R.Pérez-Luque,
X.Carpena,
M.Díaz,
J.C.Ferrer,
P.C.Loewen,
I.Fita.
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Ref.
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J Biol Chem, 2013,
288,
11907-11919.
[DOI no: ]
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PubMed id
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Abstract
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Decarboxylation of malonyl-CoA to acetyl-CoA by malonyl-CoA decarboxylase (MCD;
EC 4.1.1.9) is an essential facet in the regulation of fatty acid metabolism.
The structure of human peroxisomal MCD reveals a molecular tetramer that is best
described as a dimer of structural heterodimers, in which the two subunits
present markedly different conformations. This molecular organization is
consistent with half-of-the-sites reactivity. Each subunit has an all-helix
N-terminal domain and a catalytic C-terminal domain with an acetyltransferase
fold (GNAT superfamily). Intersubunit disulfide bridges, Cys-206-Cys-206 and
Cys-243-Cys-243, can link the four subunits of the tetramer, imparting positive
cooperativity to the catalytic process. The combination of a half-of-the-sites
mechanism within each structural heterodimer and positive cooperativity in the
tetramer produces a complex regulatory picture that is further complicated by
the multiple intracellular locations of the enzyme. Transport into the
peroxisome has been investigated by docking human MCD onto the peroxisomal
import protein peroxin 5, which revealed interactions that extend beyond the
C-terminal targeting motif.
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