DEAD-box RNA-helicase DDX19 in complex with ADP

Human DEAD-box RNA-helicase DDX19 in complex with ADP (3ews)

About this Structure

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

• Helicase
• 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.