Skip to main content
. 2012 Nov 22;41(2):746–753. doi: 10.1093/nar/gks1126

Figure 2.

Figure 2.

Visualization of the Dan nucleoprotein filaments. (A) AFM image of linearized φX174 DNA molecules in the absence of Dan protein showed relaxed conformation. (B) Incubation with Dan protein at a 1:1 ratio of Dan to base pairs forms elongated DNA conformation, indicating that DNA stiffens on Dan binding. In addition, some of the DNA is condensed (white arrows). (C) An example of a monomeric rigid nucleoprotein filament at a 1:1 ratio of Dan to base pairs (300 nM Dan, 10 ng DNA) suggests that Dan is evenly coated along the entire DNA length. (D) High-resolution AFM images show that the Dan nucleoprotein adopts a periodic filament structure. (E) Close-up image of the white box in (D) indicates the periodic feature spacing, p. (F) Semi-empirical measurements of the feature spacing, p, suggests there is a regular spacing of ∼50 nm (N = 95). (G) The hypothesized helical structure of the Dan nucleoprotein filament with a periodic protein filament (orange spheres) wrapping along DNA (black line).