Format

Send to

Choose Destination
Structure. 2010 Feb 10;18(2):177-87. doi: 10.1016/j.str.2009.12.011.

Structural basis for DNA strand separation by the unconventional winged-helix domain of RecQ helicase WRN.

Author information

1
Structural Biology Laboratory, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan. kkitano@is.naist.jp

Abstract

The RecQ family of DNA helicases including WRN (Werner syndrome protein) and BLM (Bloom syndrome protein) protects the genome against deleterious changes. Here we report the cocrystal structure of the RecQ C-terminal (RQC) domain of human WRN bound to a DNA duplex. In the complex, the RQC domain specifically interacted with a blunt end of the duplex and, surprisingly, unpaired a Watson-Crick base pair in the absence of an ATPase domain. The beta wing, an extended hairpin motif that is characteristic of winged-helix motifs, was used as a "separating knife" to wedge between the first and second base pairs, whereas the recognition helix, a principal component of helix-turn-helix motifs that are usually embedded within DNA grooves, was unprecedentedly excluded from the interaction. Our results demonstrate a function of the winged-helix motif central to the helicase reaction, establishing the first structural paradigm concerning the DNA structure-specific activities of the RecQ helicases.

Comment in

PMID:
20159463
DOI:
10.1016/j.str.2009.12.011
[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center