Electron microscopy articles from across Nature Portfolio

Spliceosome biogenesis and recycling remains a largely unexplored area. Two papers now reveal how protein chaperones remodel the 20S U5 snRNP, leading to formation of the U4/U6.U5 tri-snRNP.

The carbon fixation machinery α-carboxysome of the marine cyanobacterium Prochlorococcus is composed of an icosahedral-like proteinaceous shell that encapsulates the enzymes RuBisCO and carbonic anhydrase. Our cryo-EM structure reveals how thousands of protein components self-assemble into the α-carboxysome and characterizes the multivalent interactions by which the scaffolding protein CsoS2 crosslinks the shell with internal RuBisCO molecules.

In C. elegans, systemic RNAi is initiated by SID-1-mediated dsRNA internalization. Here the authors present cryo-EM structures of SID-1 homologs and the SID-1–dsRNA complex, elucidating the structural basis for dsRNA recognition and uptake by SID-1.

ESI-cryoPrep is a cryo-EM specimen preparation method that employs electrospray ionization techniques to deposit charged macromolecule-containing droplets on EM grids. Demonstrated across various protein samples, this approach effectively prevents biomolecule adsorption at air–water or graphene–water interfaces, addressing challenges related to protein denaturation and preferred orientation.

Single-stranded DNA annealing is driven by RAD52 open rings in association with RPA.

Here, the authors structurally and functionally characterise DltB, a member of the Membrane-Bound O-AcylTransferase (MBOAT) superfamily responsible for D-alanine incorporation in the cell wall of gram-positive bacteria.

Spliceosome biogenesis and recycling remains a largely unexplored area. Two papers now reveal how protein chaperones remodel the 20S U5 snRNP, leading to formation of the U4/U6.U5 tri-snRNP.

The carbon fixation machinery α-carboxysome of the marine cyanobacterium Prochlorococcus is composed of an icosahedral-like proteinaceous shell that encapsulates the enzymes RuBisCO and carbonic anhydrase. Our cryo-EM structure reveals how thousands of protein components self-assemble into the α-carboxysome and characterizes the multivalent interactions by which the scaffolding protein CsoS2 crosslinks the shell with internal RuBisCO molecules.

G protein-coupled receptors (GPCRs) with no known endogenous ligand are termed orphans. Deorphanization of a GPCR involves identifying the ligand, which can be a painstaking exercise. In this Comment, we discuss the challenges in the process, its role in drug discovery and alternative approaches to characterizing orphan GPCRs.

Reporting in Nature Communications, Huo and colleagues provide three-dimensional structures of a bacterial immune defense system called Gabija. This work builds on recently published structural and functional studies and contributes strong evidence that protein assembly formation is essential for antiviral function.