title: A family portrait: structural comparison of the Whirly proteins from Arabidopsis thaliana and Solanum tuberosum.
abstract: DNA double-strand breaks are highly detrimental genomic lesions that routinely arise in genomes. To protect the integrity of their genetic information, all organisms have evolved specialized DNA-repair mechanisms. Whirly proteins modulate DNA repair in plant chloroplasts and mitochondria by binding single-stranded DNA in a non-sequence-specific manner. Although most of the results showing the involvement of the Whirly proteins in DNA repair have been obtained in Arabidopsis thaliana, only the crystal structures of the potato Whirly proteins WHY1 and WHY2 have been reported to date. The present report of the crystal structures of the three Whirly proteins from A. thaliana (WHY1, WHY2 and WHY3) reveals that these structurally similar proteins assemble into tetramers. Furthermore, structural alignment with a potato WHY2-DNA complex reveals that the residues in these proteins are properly oriented to bind single-stranded DNA in a non-sequence-specific manner.
authors.affiliation: Department of Biochemistry, Université de Montréal, PO Box 6128, Station Centre-Ville, Montréal, Québec H3C 3J7, Canada.
authors.forename: Laurent
authors.initials: L
authors.lastname: Cappadocia
authors.forename: Jean-Sébastien
authors.initials: JS
authors.lastname: Parent
authors.forename: Jurgen
authors.initials: J
authors.lastname: Sygusch
authors.forename: Normand
authors.initials: N
authors.lastname: Brisson
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000737:chemistry*; D029681:Arabidopsis Proteins / Q000737:chemistry*; D001665:Binding Sites; D002736:Chloroplasts / Q000378:metabolism; D017124:Conserved Sequence; D018360:Crystallography, X-Ray; D018744:DNA, Plant / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry*; D011485:Protein Binding; D016415:Sequence Alignment; D011198:Solanum tuberosum / Q000737:chemistry*; D040681:Structural Homology, Protein
chemical_list: D029681:Arabidopsis Proteins; D018744:DNA, Plant; D010940:Plant Proteins
keywords: Arabidopsis; DNA repair; WHY1; WHY2; WHY3; Whirly proteins; ssDNA-binding proteins