Multilayer DNA Origami with Terminal Interfaces That Are Flat and Wide-Area.

DNA origami is a popular nanofabrication strategy that employs self-assembly of a long single scaffold strand, typically less than 10 kilobases in length, with hundreds of shorter staple strands into a desired shape. In particular, origami arranged as a single-layer rectangle has proven popular as flat pegboards that can display functionalities at staple-strand breakpoints, off the sides of the constituent double helices, with a ∼5.3 nm rhombic-lattice spacing.

Structure of the peroxisomal Pex1/Pex6 ATPase complex bound to a substrate.

The double-ring AAA+ ATPase Pex1/Pex6 is required for peroxisomal receptor recycling and is essential for peroxisome formation. Pex1/Pex6 mutations cause severe peroxisome associated developmental disorders. Despite its pathophysiological importance, mechanistic details of the heterohexamer are not yet available.

Asymmetric horseshoe-like assembly of peroxisomal yeast oxalyl-CoA synthetase.

Oxalyl-CoA synthetase from is one of the most abundant peroxisomal proteins in yeast and hence has become a model to study peroxisomal translocation. It contains a C-terminal Peroxisome Targeting Signal 1, which however is partly dispensable, suggesting additional receptor bindings sites. To unravel any additional features that may contribute to its capacity to be recognized as peroxisomal target, we determined its assembly and overall architecture by an integrated structural biology approach, including X-ray crystallography, single particle cryo-electron microscopy and small angle X-ray scattering.

Three-phase DNA-origami stepper mechanism based on multi-leg interactions.

Nanoscale stepper motors such as kinesin and dynein play a key role in numerous natural processes such as mitotic spindle formation during cell division or intracellular organelle transport. Their high efficacy in terms of operational speed and processivity has inspired the investigation of biomimetic technologies based on the use of programmable molecules. In particular, several designs of molecular walkers have been explored using DNA nanotechnology.

Coordination Cage-Based Emulsifiers: Templated Formation of Metal Oxide Microcapsules Monitored by In Situ LC-TEM.

Metallo-supramolecular self-assembly has yielded a plethora of discrete nanosystems, many of which show competence in capturing guests and catalyzing chemical reactions. However, the potential of low-molecular bottom-up self-assemblies in the development of structured inorganic materials has rarely been methodically explored so far. Herein, we present a new type of metallo-supramolecular surfactant with the ability to stabilize non-aqueous emulsions for a significant period.

Towards the molecular architecture of the peroxisomal receptor docking complex.

Import of yeast peroxisomal matrix proteins is initiated by cytosolic receptors, which specifically recognize and bind the respective cargo proteins. At the peroxisomal membrane, the cargo-loaded receptor interacts with the docking protein Pex14p that is tightly associated with Pex17p. Previous data suggest that this interaction triggers the formation of an import pore for further translocation of the cargo.

Insights into the Structure and Energy of DNA Nanoassemblies.

Since the pioneering work of Ned Seeman in the early 1980s, the use of the DNA molecule as a construction material experienced a rapid growth and led to the establishment of a new field of science, nowadays called structural DNA nanotechnology. Here, the self-recognition properties of DNA are employed to build micrometer-large molecular objects with nanometer-sized features, thus bridging the nano- to the microscopic world in a programmable fashion. Distinct design strategies and experimental procedures have been developed over the years, enabling the realization of extremely sophisticated structures with a level of control that approaches that of natural macromolecular assemblies.

SPHIRE-crYOLO is a fast and accurate fully automated particle picker for cryo-EM.

Selecting particles from digital micrographs is an essential step in single-particle electron cryomicroscopy (cryo-EM). As manual selection of complete datasets-typically comprising thousands of particles-is a tedious and time-consuming process, numerous automatic particle pickers have been developed. However, non-ideal datasets pose a challenge to particle picking.

Rational Design of an Amphiphilic Coordination Cage-Based Emulsifier.

Self-assembled, porous coordination cages with a functional interior find application in controlled guest inclusion/release, drug delivery, separation processes, and catalysis. However, only few studies exist that describe their utilization for the development of self-assembled materials based on their 3-dimensional shape and external functionalization. Here, dodecyl chain-containing, acridone-based ligands (L) and shape-complementary phenanthrene-derived ligands (L) are shown to self-assemble to heteroleptic coordination cages cis-[Pd(L)(L)] acting as a gemini amphiphile (CGA-1; Cage-based Gemini Amphiphile-1).

Hierarchical Assembly of DNA Filaments with Designer Elastic Properties.

The elastic features of protein filaments are encoded in their component units and in the way they are connected, thus defining a biunivocal relationship between the monomer and the result of its self-assembly. Using DNA origami approaches, we constructed a reconfigurable module, composed of two quasi-independent domains and four possible interfaces, capable of facial and lateral growing through specific recognition patterns. Whereas the flexibility of the intra-domains region can be regulated by switchable DNA motifs, the inter-domain interfaces feature mutually and self-complementary shapes, whose pairwise association leads to filaments of programmable periodicity and variable persistence length.

Tailored protein encapsulation into a DNA host using geometrically organized supramolecular interactions.

The self-organizational properties of DNA have been used to realize synthetic hosts for protein encapsulation. However, current strategies of DNA-protein conjugation still limit true emulation of natural host-guest systems, whose formation relies on non-covalent bonds between geometrically matching interfaces. Here we report one of the largest DNA-protein complexes of semisynthetic origin held in place exclusively by spatially defined supramolecular interactions.