Practical components for three-dimensional molecular nanofabrication must be simple to produce, stereopure, rigid, and adaptable. We report a family of DNA tetrahedra, less than 10 nanometers on side, that can self-assemble in seconds with near-quantitative yield one diastereomer. They connected by programmable linkers. Their triangulated architecture confers structural stability; compressing tetrahedron an atomic force microscope, we have measured the axial compressibility observed buckling...

A tetrahedral nanostructure whose edges are DNA double helices self-assembles spontaneously when four appropriately designed oligonucleotides annealed together in solution; the ease of synthesis, rigidity, and adaptability this construct make it a promising candidate as cage for other large molecules building block more complicated nanostructures.

An environmentally friendly procedure for the surface modification of cellulose nanocrystals (CNCs) in water is presented. Tannic acid (TA), a plant polyphenol, acts as primer when mixed with CNCs suspension, which are then reacted decylamine (DA), hydrophobe. Schiff base formation/Michael-type addition covalently attaches primary amines long alkyl tails to CNC-TA, increasing particle hydrophobicity (contact angle shift from 21 74°). After modification, CNC-TA-DA particles phase separate,...

Torque is generated in the rotary motor at base of bacterial flagellum by ion translocating stator units anchored to peptidoglycan cell wall. Stator are composed proteins MotA and MotB proton-driven motors, they PomA PomB sodium-driven motors. Strains Escherichia coli lacking functional produce flagella that do not rotate, induced expression missing leads restoration rotation discrete speed increments, a process known as “resurrection.” Early work suggested maximum eight units. More recent...

Complex Cooperativity in multisubunit protein complexes is classically understood terms of either a concerted model, which all subunits switch conformation simultaneously, or sequential subunit switches whenever ligand binds. More recently, “conformational spread” model has suggested that conformational coupling between and probabilistic. Using high-resolution optical microscopy, Bai et al. (p. 685 ; see the Perspective by Hilser ) observed multistate switching bacterial flagellar complex...

The twin-arginine translocation (Tat) system transports folded proteins across the bacterial cytoplasmic membrane and thylakoid of plant chloroplasts. essential components Tat pathway are TatA, TatB, TatC. TatA is thought to form protein translocating element system. Current models for transport make predictions about oligomeric state whether, how, this changes during cycle. We determined directly at native levels expression in living cells by photophysical analysis individual yellow...

It is becoming clear that the bacterial flagellar motor output important not only for locomotion but also mediating transition from liquid to surface living. The of changes with mechanical load placed on it by external environment: at a higher load, runs more slowly and produces torque. Here we show number torque-generating units bound depends fewer stators lower loads. Stalled motors contained least as many rotating high indicating rotation unnecessary stator binding. Mutant incapable...

Most biological processes are performed by multiprotein complexes. Traditionally described as static entities, evidence is now emerging that their components can be highly dynamic, exchanging constantly with cellular pools. The bacterial flagellar motor contains ∼13 different proteins and provides an ideal system to study functional molecular It powered transmembrane ion flux through a ring of stator complexes push on central rotor. Escherichia coli switches direction stochastically in...

A green approach to anchor silver nanoparticles (AgNPs) onto the surface of cellulose nanocrystals (CNCs) coated with mussel-inspired polydopamine (PDA) at room temperature in absence a stabilizer and reducing agent is proposed. The resulting nanohybrids possessed core–shell structure numerous "satellites" decorating CNC surface. nanocatalyst displayed superior dispersibility over pristine AgNPs was six times more efficient catalyzing reduction 4-nitrophenol. By associating hybrid...

The aggregation of nanoparticles has been shown to significantly reduce the activity nanomaterials, resulting in inferior performance. As an alternative use traditional capping agents, stabilization unstable with water-dispersible and biocompatible carriers is a promising strategy. A bioinspired coating strategy was developed hybrid displayed excellent colloidal stability that improved antibacterial when silver (AgNPs) were used as model. Cellulose nanocrystals (CNCs) first modified...

Myxococcus xanthus is a Gram-negative bacterium that glides over surfaces without the aid of flagella. Two motility systems are used for locomotion: social-motility, powered by retraction type IV pili, and adventurous (A)-motility, unknown mechanism(s). We have shown AgmU, an A-motility protein, part multiprotein complex spans inner membrane periplasm M. xanthus. In this paper, we present evidence periplasmic AgmU decorates looped continuous helix rotates clockwise as cells glide forward,...

This paper reports on the synthesis of β-cyclodextrin-modified CNC@Fe3O4@SiO2 superparamagnetic nanorods for removal two model compounds: procaine hydrochloride and imipramine hydrochloride. During synthetic process, sustainable natural materials low-cost chemicals were used, mild reaction conditions adopted. TEM SEM images indicated good dispersion Fe3O4 nanoparticles with uniform silica coating CNCs. The thickness was controlled by manipulating amounts precursor solution used. TGA data...

Microcapsulation of phase change materials (PCMs) within a shell is one the most feasible methods to explore their applications for thermal energy storage. Here, facile method microencapsulate PCMs polystyrene/cellulose nanocrystal (CNC) hybrid via Pickering emulsion polymerization was developed. CNCs, as biobased and sustainable hydrolyzed from wood pulp, were employed emulsifiers PCM components microcapsules well. CNCs displayed high efficiency in stabilization paraffin wax (PW) emulsion,...

Structural colors and photoluminescence have been widely used for anti-counterfeiting security applications. We report the first time use of CdS quantum dot (QD)-functionalized cellulose nanocrystals (CNCs) as building blocks to fabricate nanothin films via layer-by-layer (LBL) self-assembly Both negatively- positively-charged CNC/QD nanohybrids with a high colloidal stability narrow particle size distribution were prepared. The controllable LBL coating process was characterized by scanning...

F1Fo ATP synthase functions as a biological rotary generator that makes major contribution to cellular energy production. It comprises two molecular motors coupled together by central and peripheral stalk. Proton flow through the Fo motor generates rotation of stalk, inducing conformational changes in F1 catalyzes Here we present nine cryo-EM structures E. coli 3.1-3.4 Å resolution, four discrete rotational sub-states, which provide comprehensive structural model for this widely studied...

The injectisome is a membrane complex through which some bacteria can inject effector proteins into host cells. This study reveals that the cytosolic C-ring structure has dynamic relationship to rest of injectisome, with implications for regulation secretion.