Abstract
DNA overwinding and
underwinding between adjacent Holliday junctions have been applied in DNA
origami constructs to design both left-handed and right-handed nanostructures. For
a variety of DNA tubes assembled from small tiles, only an abstract concept of
the intrinsic tile curvature was previously used to explain their formation.
Details regarding the quantitative and structural descriptions of the intrinsic
tile curvature and its evolution in DNA tubes by coupling with arm twists have
been lacking. In this work, we designed three types of tile cores from a
circular 128 nucleotide scaffold by longitudinal weaving (LW), bridging
longitudinal weaving (bLW), and transverse weaving (TW) and assembled their 2D
planar or tubular nanostructures via inter-tile arms with a distance of an odd
or even number of DNA half-turns. The biotin/streptavidin (SA) labeling technique
was applied to define the tube configuration with addressable inside and
outside surfaces and thus their component tile conformation with addressable
concave and convex curvatures. Both chiral tubes possessing left-handed and
right-handed curvatures could be generated by finely tuning p and q in bLW-Ep/q
designs (bLW tile cores joined together by inter-tile arms of even
number of half-turns with the arm length of p base pairs (bp) and the sticky
end length of q nucleotides (nt)). We were able to assign the chiral indices
(n,m) to each specific tube from the high-resolution AFM images, and thus
estimated the tile curvature angle with a regular polygon model that
approximates each tube’s transverse section. We attribute the curvature
evolution of bLW-Ep/q tubes composed of the same tile core to the
coupling of the intrinsic tile curvature and different arm twists. A better
understanding of integrated actions of different types of twisting forces on
DNA tubes will be much more helpful in engineering DNA nanostructures in the
future.
Supplementary materials
Title
Supporting Information
Description
Actions