Abstract
Multihelical DNA bundles could enhance the functionality of nanomaterials and serve as model architectures to mimic protein filaments on the molecular and cellular level. We report the self-assembly of micrometer-sized helical DNA nanotubes with widely controllable helical diameters ranging from tens of nanometers to a few micrometers. Nanoscale helical shapes of DNA tile tubes (4-, 6-, 8-, 10-, and 12-helix tile tubes) are achieved by introducing discrete amounts of bending and twist through base pair insertions and/or deletions. Microscale helical diameters, which require smaller amounts of twist and bending, are achieved by controlling the intrinsic "supertwist" present in tile tubes with uneven number of helices (11-, 13-, and 15-helix tile tubes). Supertwist fine-tuning also allows us to produce helical nanotubes of defined chirality.