Solution structure of a multifunctional DNA- and protein-binding motif of human Werner syndrome protein

Abstract

Werner syndrome (WS) is an autosomal recessive disease that results in premature aging. Mutations in the WS gene (WRN) result in a loss of expression of the WRN protein and predispose WS patients to accelerated aging. As a helicase and a nuclease, WRN is unique among the five human RecQ helicase family members and is capable of multiple functions involved in DNA replication, repair, recombination, and telomere maintenance. A 144-residue fragment of WRN was previously determined to be a multifunctional DNA-and protein-binding domain (DPBD) that interacts with structure-specific DNA and a variety of DNA-processing proteins. In addition, DPBD functions as a nucleolar targeting sequence of WRN. The solution structure of the DPBD, the first of a WRN fragment, has been solved by NMR. DPBD consists of a winged helix-like motif and an unstructured C-terminal region of Ϸ20 aa. The putative DNA-binding surface of DPBD has been identified by using known structural and biochemical data. Based on the structural data and on the biochemical data, we suggest a surface on the DPBD for interacting with other proteins. In this structural model, a single winged helix domain binds to both DNA and other proteins. Furthermore, we propose that DPBD functions as a regulatory domain to regulate the enzymatic activity of WRN and to direct cellular localization of WRN through protein-protein interaction.DNA-and protein-binding domain ͉ functional regulation ͉ NMR structure ͉ winged helix

The Human Werner Syndrome Protein Stimulates Repair of Oxidative DNA Base Damage by the DNA Glycosylase NEIL1

“…The lack of association between WRN and OGG1, another glycosylase, underscores the specificity of WRN and NEIL1 binary interaction. We have shown here that the C-terminal RQC domain of WRN, the major DNA and protein binding domain (56), is sufficient to mediate the interaction with NEIL1 and to stimulate oxidative base incision by NEIL1 in an ATP-independent manner. Kinetic analyses of the NEIL1 cleavage reaction for damage-containing substrates further demonstrate that WRN increases the catalytic specificity of NEIL1 by affecting the reaction rate at subsaturating DNA concentrations.…”

RecQ helicases: Multiple structures for multiple functions?

“…However, the crystal structures of the WH domains of E. coli RecQ and human RECQ1, and the NMR derived structure of the equivalent domain in human WRN, show a very well conserved domain organization Hu et al, 2005;Pike et al, 2008). This structural unit is characterized by a helix-turn-helix fold that is also present in variety of DNA binding proteins, such as the transcription factors CAP and hRFX1, and the human DNA repair protein AGT (Daniels et al, 2004;Schultz et al, 1991).…”

Three HRDC Domains Differentially Modulate Deinococcus radiodurans RecQ DNA Helicase Biochemical Activity

“…binding and winged helix subdomains that are thought to be important for structural stability and interactions with DNA and proteins (25)(26)(27). HRDC domains have been found in both ribonucleases and helicases, suggesting a broad role in nucleic acid binding (23), and isolated HRDC domains from EcRecQ, Saccharomyces cerevisiae Sgs1, and human WRN all bind DNA, albeit with different structural preferences (28 -30).…”