Composite, helical nanostructures formed using cooperative interactions of liquid crystals and Au nanoparticles were studied using a scanning transmission electron microscopy (STEM) mode. The investigated helical assemblies exhibit long-range hierarchical order across length scales, as a result of the crystallization (freezing) directed growth mechanism of nanoparticle-coated twisted nanoribbons and their ability to form organized bundles. Here, STEM methods were used to reproduce the 3D structure of the Au nanoparticle double helix.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1017/S1431927621012009 | DOI Listing |
SSNA-1 is a fibrillar protein localized at the area where dynamic microtubule remodeling occurs including centrosomes. Despite the important activities of SSNA1 to microtubules such as nucleation, co-polymerization, and lattice sharing microtubule branching, the underlying molecular mechanism have remained unclear due to a lack of structural information. Here, we determined the cryo-EM structure of SSNA-1 at 4.
View Article and Find Full Text PDFbioRxiv
December 2024
Rutherford Appleton Laboratory, Research Complex at Harwell, Didcot, Oxfordshire, UK.
Conjugation, the major driver of the spread of antimicrobial resistance genes, relies on a conjugation pilus for DNA transfer. Conjugative pili, such as the F-pilus, are dynamic tubular structures, composed of a polymerized pilin, that mediate the initial donor-recipient interactions, a process known as mating pair formation (MPF). IncH are low-copy-number plasmids, traditionally considered broad host range, which are found in bacteria infecting both humans and animals.
View Article and Find Full Text PDFNat Commun
January 2025
Institute of Bioanalytical Chemistry, Faculty of Chemistry and Mineralogy, Universität Leipzig, Leipzig, Germany.
The proline-rich antimicrobial designer peptide Api137 inhibits protein expression in bacteria by binding simultaneously to the ribosomal polypeptide exit tunnel and the release factor (RF), depleting the cellular RF pool and leading to ribosomal arrest at stop codons. This study investigates the additional effect of Api137 on the assembly of ribosomes using an Escherichia coli reporter strain expressing one ribosomal protein per 30S and 50S subunit tagged with mCherry and EGFP, respectively. Separation of cellular extracts derived from cells exposed to Api137 in a sucrose gradient reveals elevated levels of partially assembled and not fully matured precursors of the 50S subunit (pre-50S).
View Article and Find Full Text PDFActa Histochem
January 2025
School of Chemistry, University of Glasgow, Glasgow G12 8QQ, UK.
In recent years, a great interest has been focused on the prebiotic origin of nucleic acids and life on Earth. An attractive idea is that life was initially based on an autocatalytic and autoreplicative RNA (the RNA-world). RNA duplexes are right-handed helical chains with antiparallel orientation, but the rationale for these features is not yet known.
View Article and Find Full Text PDFDalton Trans
January 2025
Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Materials Science Heilongjiang University, 74 Xuefu Road, Harbin 150080, China.
Herein, we report the influence of solvent on the self-assembly of a dinuclear helicate, (NMe)[Eu(LR)]. A multiple species mixture with the chemical composition of [Eu(LR)] present in CHCN can be transformed into a helicate upon increasing the content of CHCl, accompanied by a significant enhancement in circularly polarized luminescence activity.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!