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PDBsum entry 3g0h
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Hydrolase/RNA
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PDB id
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3g0h
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References listed in PDB file
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Key reference
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Title
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The dexd/h-Box RNA helicase ddx19 is regulated by an {alpha}-Helical switch.
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Authors
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R.Collins,
T.Karlberg,
L.Lehtiö,
P.Schütz,
S.Van den berg,
L.G.Dahlgren,
M.Hammarström,
J.Weigelt,
H.Schüler.
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Ref.
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J Biol Chem, 2009,
284,
10296-10300.
[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 have
been manually determined.
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Abstract
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DEXD/H-box RNA helicases couple ATP hydrolysis to RNA remodeling by an unknown
mechanism. We used x-ray crystallography and biochemical analysis of the human
DEXD/H-box protein DDX19 to investigate its regulatory mechanism. The crystal
structures of DDX19, in its RNA-bound prehydrolysis and free posthydrolysis
state, reveal an alpha-helix that inserts between the conserved domains of the
free protein to negatively regulate ATPase activity. This finding was
corroborated by biochemical data that confirm an autoregulatory function of the
N-terminal region of the protein. This is the first study describing crystal
structures of a DEXD/H-box protein in its open and closed cleft conformations.
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Figure 1.
Structure of human DDX19. A, overview of DDX19 with ADP bound
and the N-terminal flanking helix in the central cleft. The
Arg^429 side chain that acts as an arginine finger is presented
as sticks. B, schematic representation of the cleft-inserted
helix with the two conserved domains of the protein, shown in
the same view as in panel A. Residues that are conserved in
DDX25 are shown in blue. C, overview of the DDX19-RNA complex,
with Mg-ADPNP bound in the central cleft. The Arg^429 side chain
is presented as sticks. D, detail of the RNA binding site of the
DDX19-RNA complex. E, detail of the nucleotide binding site in
the open conformation, with the electron density (2F[obs] –
F[calc]) for ADP rendered at 1.5 σ. F, detail of the nucleotide
binding site in the RNA complex, with the electron density
(2F[obs] – F[calc]) for Mg-ADPNP rendered at 1.5 σ. In all
panels, the conserved domain-1 (yellow), the conserved domain-2
(red), and the N-terminal flanking sequence (green) are
indicated.
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Figure 2.
Role of the N-terminal flanking sequence in the regulation of
DDX19 ATPase activity. A, schematic diagram of the DDX19 protein
constructs used in this study (not drawn to scale). N-term
represents the N terminus. B, relative ATPase activities of
DDX19 protein constructs in the presence of between 0 and 0.5
mg/ml ssRNA.
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The above figures are
reprinted
from an Open Access publication published by the ASBMB:
J Biol Chem
(2009,
284,
10296-10300)
copyright 2009.
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