2kmu

Publication Abstract from PubMed

The RecQL4 helicase is involved in the maintenance of genome integrity and DNA replication. Mutations in the human RecQL4 gene cause the Rothmund-Thomson, RAPADILINO and Baller-Gerold syndromes. Mouse models and experiments in human and Xenopus have proven the N-terminal part of RecQL4 to be vital for cell growth. We have identified the first 54 amino acids of RecQL4 (RecQL4_N54) as the minimum interaction region with human TopBP1. The solution structure of RecQL4_N54 was determined by heteronuclear liquid-state nuclear magnetic resonance (NMR) spectroscopy (PDB 2KMU; backbone root-mean-square deviation 0.73 A). Despite low-sequence homology, the well-defined structure carries an overall helical fold similar to homeodomain DNA-binding proteins but lacks their archetypical, minor groove-binding N-terminal extension. Sequence comparison indicates that this N-terminal homeodomain-like fold is a common hallmark of metazoan RecQL4 and yeast Sld2 DNA replication initiation factors. RecQL4_N54 binds DNA without noticeable sequence specificity yet with apparent preference for branched over double-stranded (ds) or single-stranded (ss) DNA. NMR chemical shift perturbation observed upon titration with Y-shaped, ssDNA and dsDNA shows a major contribution of helix alpha3 to DNA binding, and additional arginine side chain interactions for the ss and Y-shaped DNA.

The N-terminus of the human RecQL4 helicase is a homeodomain-like DNA interaction motif.,Ohlenschlager O, Kuhnert A, Schneider A, Haumann S, Bellstedt P, Keller H, Saluz HP, Hortschansky P, Hanel F, Grosse F, Gorlach M, Pospiech H Nucleic Acids Res. 2012 Sep 1;40(17):8309-24. Epub 2012 Jun 22. PMID:22730300^[2]

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