Transcriptional Interference in Toehold Switch-Based RNA Circuits.

Gene regulation based on regulatory RNA is an important mechanism in cells and is increasingly used for regulatory circuits in synthetic biology. Toehold switches are rationally designed post-transcriptional riboregulators placed in the 5' untranslated region of mRNA molecules. In the inactive state of a toehold switch, the ribosome-binding site is inaccessible to the ribosome.

Bacterial Growth, Communication, and Guided Chemotaxis in 3D-Bioprinted Hydrogel Environments.

Bioprinting of engineered bacteria is of great interest for applications of synthetic biology in the context of living biomaterials, but so far, only a few viable approaches are available for the printing of gels hosting live bacteria. Here, we develop a gentle extrusion-based bioprinting method based on an inexpensive alginate/agarose ink mixture that enables printing of into three-dimensional hydrogel structures up to 10 mm in height. We first characterize the rheological properties of the gel ink and then study the growth of the bacteria inside printed structures.

Evaluation of an E. coli Cell Extract Prepared by Lysozyme-Assisted Sonication via Gene Expression, Phage Assembly and Proteomics.

Over the past decades, starting from crude cell extracts, a variety of successful preparation protocols and optimized reaction conditions have been established for the production of cell-free gene expression systems. One of the crucial steps during the preparation of cell extract-based expression systems is the cell lysis procedure itself, which largely determines the quality of the active components of the extract. Here we evaluate the utility of an E.

Small Antisense DNA-Based Gene Silencing Enables Cell-Free Bacteriophage Manipulation and Genome Replication.

Cell-free systems allow interference with gene expression processes without requiring elaborate genetic engineering procedures. This makes it ideally suited for rapid prototyping of synthetic biological parts. Inspired by nature's strategies for the control of gene expression short antisense RNA molecules, we here investigated the use of small DNA (sDNA) for translational inhibition in the context of cell-free protein expression.

Long-range movement of large mechanically interlocked DNA nanostructures.

Interlocked molecules such as catenanes and rotaxanes, connected only via mechanical bonds have the ability to perform large-scale sliding and rotational movements, making them attractive components for the construction of artificial molecular machines and motors. We here demonstrate the realization of large, rigid rotaxane structures composed of DNA origami subunits. The structures can be easily modified to carry a molecular cargo or nanoparticles.