The DbpA catalytic core unwinds double-helix substrates by directly loading on them
- Corresponding author: eda.koculi{at}ucf.edu
Abstract
DbpA is a DEAD-box RNA helicase implicated in the assembly of the large ribosomal subunit. Similar to all the members of the DEAD-box family, the DbpA protein has two N-terminal RecA-like domains, which perform the RNA unwinding. However, unlike other members of this family, the DbpA protein also possesses a structured C-terminal RNA-binding domain that mediates specific tethering of DbpA to hairpin 92 of the Escherichia coli 23S ribosomal RNA. Previous studies using model RNA molecules containing hairpin 92 show that the RNA molecules support the DbpA protein's double-helix unwinding activity, provided that the double helix has a 3′ single-stranded region. The 3′ single-stranded region was suggested to be the start site of the DbpA protein's catalytic unwinding activity. The data presented here demonstrate that the single-stranded region 3′ of the double-helix substrate is not required for the DbpA protein's unwinding activity and the DbpA protein unwinds the double-helix substrates by directly loading on them.
Keywords
Footnotes
-
Article published online ahead of print. Article and publication date are at http://www.rnajournal.org/cgi/doi/10.1261/rna.052928.115.
- Received June 21, 2015.
- Accepted December 2, 2015.
This article is distributed exclusively by the RNA Society for the first 12 months after the full-issue publication date (see http://rnajournal.cshlp.org/site/misc/terms.xhtml). After 12 months, it is available under a Creative Commons License (Attribution-NonCommercial 4.0 International), as described at http://creativecommons.org/licenses/by-nc/4.0/.
