title: RecA-double stranded DNA complexes studied by atomic force microscopy.
abstract: RecA-double stranded (ds) DNA complexes have been studied by atomic force microscopy (AFM). When the complexes were prepared in the presence of ATP gamma S, fully covered RecA-dsDNA filaments were observed by AFM. When the concentration of RecA proteins was lower, various lengths of filaments were found. The variation of the observed structures may directly reflect the real distribution of the intermediate complexes in the reaction mixture, as the mixture was simply deposited on a mica surface for AFM observation without special fixation or staining. The use of a carbon nanotube (CNT) AFM tip enabled high resolution to reveal the periodicity of RecA-dsDNA filaments. Our observations demonstrated the potential of the AFM method for the structural studies of the RecA-dsDNA complexes, especially their intermediate states.
authors.affiliation: Joint Research Center for Atom Technology, 1-1-4 Higashi, Tsukuba, Ibaraki 305-0046, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Umemura
authors.forename: J
authors.initials: J
authors.lastname: Komatsu
authors.forename: T
authors.initials: T
authors.lastname: Uchihashi
authors.forename: N
authors.initials: N
authors.lastname: Choi
authors.forename: S
authors.initials: S
authors.lastname: Ikawa
authors.forename: T
authors.initials: T
authors.lastname: Nishinaka
authors.forename: T
authors.initials: T
authors.lastname: Shibata
authors.forename: Y
authors.initials: Y
authors.lastname: Nakayama
authors.forename: S
authors.initials: S
authors.lastname: Katsura
authors.forename: A
authors.initials: A
authors.lastname: Mizuno
authors.forename: H
authors.initials: H
authors.lastname: Tokumoto
authors.forename: M
authors.initials: M
authors.lastname: Ishikawa
authors.forename: R
authors.initials: R
authors.lastname: Kuroda
mesh_terms: D000255:Adenosine Triphosphate / Q000031:analogs & derivatives*; D004269:DNA, Bacterial / Q000737:chemistry* / Q000648:ultrastructure*; D046911:Macromolecular Substances; D018625:Microscopy, Atomic Force / Q000295:instrumentation / Q000379:methods*; D036103:Nanotechnology; D037742:Nanotubes, Carbon; D011938:Rec A Recombinases / Q000737:chemistry* / Q000648:ultrastructure*
chemical_list: D004269:DNA, Bacterial; D046911:Macromolecular Substances; D037742:Nanotubes, Carbon; C022571:adenosine 5'-O-(3-thiotriphosphate); D000255:Adenosine Triphosphate; D011938:Rec A Recombinases