title: High-affinity RNA binding by a hyperthermophilic single-stranded DNA-binding protein.
abstract: Single-stranded DNA-binding proteins (SSBs), including replication protein A (RPA) in eukaryotes, play a central role in DNA replication, recombination, and repair. SSBs utilise an oligonucleotide/oligosaccharide-binding (OB) fold domain to bind DNA, and typically oligomerise in solution to bring multiple OB fold domains together in the functional SSB. SSBs from hyperthermophilic crenarchaea, such as Sulfolobus solfataricus, have an unusual structure with a single OB fold coupled to a flexible C-terminal tail. The OB fold resembles those in RPA, whilst the tail is reminiscent of bacterial SSBs and mediates interaction with other proteins. One paradigm in the field is that SSBs bind specifically to ssDNA and much less strongly to RNA, ensuring that their functions are restricted to DNA metabolism. Here, we use a combination of biochemical and biophysical approaches to demonstrate that the binding properties of S. solfataricus SSB are essentially identical for ssDNA and ssRNA. These features may represent an adaptation to a hyperthermophilic lifestyle, where DNA and RNA damage is a more frequent event.
authors.affiliation: Biomedical Sciences Research Complex, University of St Andrews, St Andrews, KY16 9ST, UK.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Morten
authors.affiliation: School of Science and Health, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia.|School of Molecular Bioscience, University of Sydney, Sydney, NSW, 2006, Australia.
authors.forename: Roland
authors.initials: R
authors.lastname: Gamsjaeger
authors.affiliation: School of Science and Health, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia.|School of Molecular Bioscience, University of Sydney, Sydney, NSW, 2006, Australia.
authors.forename: Liza
authors.initials: L
authors.lastname: Cubeddu
authors.affiliation: School of Science and Health, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia.|School of Molecular Bioscience, University of Sydney, Sydney, NSW, 2006, Australia.
authors.forename: Ruvini
authors.initials: R
authors.lastname: Kariawasam
authors.affiliation: Biomedical Sciences Research Complex, University of St Andrews, St Andrews, KY16 9ST, UK.
authors.forename: Jose
authors.initials: J
authors.lastname: Peregrina
authors.affiliation: Biomedical Sciences Research Complex, University of St Andrews, St Andrews, KY16 9ST, UK.
authors.forename: J Carlos
authors.initials: JC
authors.lastname: Penedo
authors.affiliation: Biomedical Sciences Research Complex, University of St Andrews, St Andrews, KY16 9ST, UK. mfw2@st-and.ac.uk.
authors.forename: Malcolm F
authors.initials: MF
authors.lastname: White
mesh_terms: D019843:Archaeal Proteins / Q000737:chemistry* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D019642:RNA, Archaeal / Q000737:chemistry* / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D048229:Sulfolobus solfataricus / Q000737:chemistry* / Q000378:metabolism
chemical_list: D019843:Archaeal Proteins; D004268:DNA-Binding Proteins; D019642:RNA, Archaeal; D016601:RNA-Binding Proteins
keywords: Förster resonance energy transger; Nuclear magnetic resonance; OB fold; RNA-binding proteins; Single-molecule dynamics