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3ews

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Contents

Human DEAD-box RNA-helicase DDX19 in complex with ADP

Publication Abstract from PubMed

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.

The DEXD/H-box RNA Helicase DDX19 Is Regulated by an {alpha}-Helical Switch., Collins R, Karlberg T, Lehtio L, Schutz P, van den Berg S, Dahlgren LG, Hammarstrom M, Weigelt J, Schuler H, J Biol Chem. 2009 Apr 17;284(16):10296-300. Epub 2009 Feb 25. PMID:19244245

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

About this Structure

3ews asymmetric unit, resolution 2.70Å.
Click to display biological molecule.
Sites: and
Ligands:
Gene: DBP5, DDX19, DDX19B (Homo sapiens)
Resources: FirstGlance, OCA, PDBsum, RCSB
Coordinates: save as pdb, mmCIF, xml


3EWS is a 2 chains structure of sequences from Homo sapiens. Full crystallographic information is available from OCA.

The is a single-chain DDX19 monomer. .

DDX19 is .

  • With ADP bound, an N-terminal extension (dark green) is wedged in a cleft between these domains negatively regulating ATPase activity by preventing cleft closure.
  • This conformation is presumed to resemble the post-hydrolysis state in which RNA is not bound. It is also referred to as the open state and open cleft conformation.
  • This scene is similar to the view in Figure 1a of the paper describing the structure. ( because Arginine 429, discussed below, is included as in that figure.)

Showing are bound.

  • This overlay clearly illustrates the dramatic shift in the location of the N-terminal extension (dark green).
  • This view clearly shows how the N-terminal helix of the extension extends from the RNA-binding site to down near the ATP binding site.

. The placement of the N-terminal extension between the two helicase domains negatively regulates ATPase activity. A .

  • Of particular note is arginine 429, the so-called arginine finger, that is essential for ATPase activity. due to the helix of the extension sitting in the cleft.
  • illustrates how it is moved to sit near the active site when RNA is bound, enabling ATPase activity.
  • Keep in mind the intermediate models, in between the endpoints, are hypothetical.

See also

3g0h is human DDX19 with a non-hydrolyzable ATP analog and mRNA mimic bound. It is used in the morphs here and was described in the same article as 3ews.

Reference

  • Collins R, Karlberg T, Lehtio L, Schutz P, van den Berg S, Dahlgren LG, Hammarstrom M, Weigelt J, Schuler H. The DEXD/H-box RNA helicase DDX19 is regulated by an {alpha}-helical switch. J Biol Chem. 2009 Apr 17;284(16):10296-300. Epub 2009 Feb 25. PMID:19244245 doi:10.1074/jbc.C900018200

Page originally seeded by OCA on Wed Apr 29 20:39:44 2009

Proteopedia Page Contributors and Editors (what is this?)

Wayne Decatur, OCA

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