title: Directed assembly of 3-nm-long RecA nucleoprotein filaments on double-stranded DNA with nanometer resolution.
abstract: Protein-mediated self-assembly is arguably one of the most promising routes for building complex molecular nanostructures. Here, we report a molecular self-assembly technique that allows programmable, site-specific patterning of double-stranded DNA scaffolds, at a single-base resolution, by 3-nm-long RecA-based nucleoprotein filaments. RecA proteins bind to single-stranded DNA to form nucleoprotein filaments. These can self-assemble onto a double-stranded DNA scaffold at a region homologous to the nucleoprotein's single-stranded DNA sequence. We demonstrate that nucleoprotein filaments can be formed from single-stranded DNA molecules ranging in length from 60 nucleotides down to just 6 nucleotides, and these can be assembled site-specifically onto a model DNA scaffold both at the end of the scaffold and away from the end. In both cases, successful site-specific self-assembly is demonstrated even for the smallest nucleoprotein filaments, which are just 3 nm long, comprise only two monomers of RecA, and cover less than one helical turn of the double-stranded DNA scaffold. Finally, we demonstrate that the RecA-mediated assembly process is highly site-specific and that the filaments indeed bind only to the homologous region of the DNA scaffold, leaving the neighboring scaffold exposed.
authors.affiliation: School of Electronic and Electrical Engineering, University of Leeds , Leeds LS2 9JT, U.K.
authors.forename: Rajan
authors.initials: R
authors.lastname: Sharma
authors.forename: A Giles
authors.initials: AG
authors.lastname: Davies
authors.forename: Christoph
authors.initials: C
authors.lastname: Wälti
mesh_terms: D004247:DNA / Q000737:chemistry*; D004277:DNA, Single-Stranded / Q000737:chemistry; D029968:Escherichia coli Proteins / Q000737:chemistry; D008958:Models, Molecular; D049329:Nanostructures / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods*; D009690:Nucleic Acid Conformation; D009698:Nucleoproteins / Q000737:chemistry*; D011938:Rec A Recombinases / Q000737:chemistry*
chemical_list: D004277:DNA, Single-Stranded; D029968:Escherichia coli Proteins; D009698:Nucleoproteins; D004247:DNA; D011938:Rec A Recombinases