title: TrmBL2 from Pyrococcus furiosus Interacts Both with Double-Stranded and Single-Stranded DNA.
abstract: In many hyperthermophilic archaea the DNA binding protein TrmBL2 or one of its homologues is abundantly expressed. TrmBL2 is thought to play a significant role in modulating the chromatin architecture in combination with the archaeal histone proteins and Alba. However, its precise physiological role is poorly understood. It has been previously shown that upon binding TrmBL2 covers double-stranded DNA, which leads to the formation of a thick and fibrous filament. Here we investigated the filament formation process as well as the stabilization of DNA by TrmBL2 from Pyroccocus furiosus in detail. We used magnetic tweezers that allow to monitor changes of the DNA mechanical properties upon TrmBL2 binding on the single-molecule level. Extended filaments formed in a cooperative manner and were considerably stiffer than bare double-stranded DNA. Unlike Alba, TrmBL2 did not form DNA cross-bridges. The protein was found to bind double- and single-stranded DNA with similar affinities. In mechanical disruption experiments of DNA hairpins this led to stabilization of both, the double- (before disruption) and the single-stranded (after disruption) DNA forms. Combined, these findings suggest that the biological function of TrmBL2 is not limited to modulating genome architecture and acting as a global repressor but that the protein acts additionally as a stabilizer of DNA secondary structure.
authors.affiliation: Department of Chemistry, University of Konstanz, Universitätsstraße 10, 78464, Konstanz, Germany.|Department of Biology, University of Konstanz, Universitätsstraße 10, 78464, Konstanz, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Wierer
authors.affiliation: Institute for Molecular Cell Biology, University of Münster, Schlossplatz 5, 48149, Münster, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Daldrop
authors.affiliation: Department of Biology, University of Konstanz, Universitätsstraße 10, 78464, Konstanz, Germany.
authors.forename: Misbha
authors.initials: M
authors.lastname: Ud Din Ahmad
authors.affiliation: Department of Biology, University of Konstanz, Universitätsstraße 10, 78464, Konstanz, Germany.
authors.forename: Winfried
authors.initials: W
authors.lastname: Boos
authors.affiliation: Department of Chemistry, University of Konstanz, Universitätsstraße 10, 78464, Konstanz, Germany.
authors.forename: Malte
authors.initials: M
authors.lastname: Drescher
authors.affiliation: Department of Biology, University of Konstanz, Universitätsstraße 10, 78464, Konstanz, Germany.
authors.forename: Wolfram
authors.initials: W
authors.lastname: Welte
authors.affiliation: Institute for Molecular Cell Biology, University of Münster, Schlossplatz 5, 48149, Münster, Germany.|Institute of Experimental Physics I, Universität Leipzig, Linnéstr. 5, 04103, Leipzig, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Seidel
mesh_terms: D019843:Archaeal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D003001:Cloning, Molecular; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D019641:DNA, Archaeal / Q000737:chemistry / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D042822:Genomic Instability / Q000235:genetics; D009690:Nucleic Acid Conformation; D011485:Protein Binding; D020027:Pyrococcus furiosus / Q000235:genetics / Q000378:metabolism
chemical_list: D019843:Archaeal Proteins; D019641:DNA, Archaeal; D004268:DNA-Binding Proteins; D004247:DNA