This study demonstrates the ability to engineer complex, twisted, and curved nanoscale shapes from DNA through programmable self-assembly. DNA strands are directed to form custom-shaped bundles of tightly crosslinked double helices, arranged in parallel to their helical axes. Targeted insertions and deletions of base pairs allow for the development of twist or curvature in the DNA bundles. The degree of curvature can be quantitatively controlled, with a radius of curvature as tight as 6 nanometers achieved. The researchers combined multiple curved elements to build intricate nanostructures, such as a wireframe beach ball or square-toothed gears. The sequences of DNA molecules can be engineered to form complex higher-order structures as multiple double-helical segments connected through turn regions. Programmable self-assembly based on DNA directed to branch in this way offers an attractive route to creating particular shapes on the 1 to 100 nm scale. The scaffold-DNA-origami method allows for the self-assembly of custom-shaped, mega-dalton-scale, planar arrays of anti-parallel helices connected through turn regions. In this method, each staple strand base-pairs along part of its length with a complementary segment of the scaffold strand, and then abruptly switches to base-pair with another complementary scaffold segment that may be quite distant in the scaffold primary sequence. The researchers extended DNA-origami to 3D nanoconstruction with a design strategy that can be conceptualized as stacking corrugated sheets of antiparallel helices. The resulting structures resemble bundles of double helices constrained to a honeycomb lattice. The number, arrangement, and individual lengths of helices can be tuned to produce a variety of 3D shapes. The study also explores the use of balanced gradients of insertions and deletions to produce global bend with no global twist by constructing seven versions of a three-row, six-helix-per-row bundle. The design contains 61 crossover planes evenly spaced along the helical axis. Between 15 crossover planes in the middle of the bundle, gradients of insertions and deletions across the short axis of the cross section were implemented. The study quantifies the distribution of bend angles for each version in the series of bundles. The results show that bend angles ranging from 30° to 180° as well as sharply bent radii of curvature down to 6 nm could be realized. The study also illustrates the diversity of curved shapes now accessible, including a DNA bundle bearing three 'teeth' that is programmed to fold into a half circle with a 25 nm radius. Using hierarchical assembly, two of these bundles can be combined into a circular object that resembles a nanoscale gear with six teeth. The study also creates three-dimensional spherical shapes, such as a 50-nm-wide spherical wireframe object that resembles a beach ball. Precisely arranged bent DNA and associated DNA-binding proteins play an important roleThis study demonstrates the ability to engineer complex, twisted, and curved nanoscale shapes from DNA through programmable self-assembly. DNA strands are directed to form custom-shaped bundles of tightly crosslinked double helices, arranged in parallel to their helical axes. Targeted insertions and deletions of base pairs allow for the development of twist or curvature in the DNA bundles. The degree of curvature can be quantitatively controlled, with a radius of curvature as tight as 6 nanometers achieved. The researchers combined multiple curved elements to build intricate nanostructures, such as a wireframe beach ball or square-toothed gears. The sequences of DNA molecules can be engineered to form complex higher-order structures as multiple double-helical segments connected through turn regions. Programmable self-assembly based on DNA directed to branch in this way offers an attractive route to creating particular shapes on the 1 to 100 nm scale. The scaffold-DNA-origami method allows for the self-assembly of custom-shaped, mega-dalton-scale, planar arrays of anti-parallel helices connected through turn regions. In this method, each staple strand base-pairs along part of its length with a complementary segment of the scaffold strand, and then abruptly switches to base-pair with another complementary scaffold segment that may be quite distant in the scaffold primary sequence. The researchers extended DNA-origami to 3D nanoconstruction with a design strategy that can be conceptualized as stacking corrugated sheets of antiparallel helices. The resulting structures resemble bundles of double helices constrained to a honeycomb lattice. The number, arrangement, and individual lengths of helices can be tuned to produce a variety of 3D shapes. The study also explores the use of balanced gradients of insertions and deletions to produce global bend with no global twist by constructing seven versions of a three-row, six-helix-per-row bundle. The design contains 61 crossover planes evenly spaced along the helical axis. Between 15 crossover planes in the middle of the bundle, gradients of insertions and deletions across the short axis of the cross section were implemented. The study quantifies the distribution of bend angles for each version in the series of bundles. The results show that bend angles ranging from 30° to 180° as well as sharply bent radii of curvature down to 6 nm could be realized. The study also illustrates the diversity of curved shapes now accessible, including a DNA bundle bearing three 'teeth' that is programmed to fold into a half circle with a 25 nm radius. Using hierarchical assembly, two of these bundles can be combined into a circular object that resembles a nanoscale gear with six teeth. The study also creates three-dimensional spherical shapes, such as a 50-nm-wide spherical wireframe object that resembles a beach ball. Precisely arranged bent DNA and associated DNA-binding proteins play an important role