Articles in 2023

Cells contain compartments composed of phase-separated protein condensates. We find that these condensates have a unique chemical microenvironment that enriches amphipathic metabolites such as phospholipids. Therefore, condensates are mixtures of proteins, nucleic acids and specific metabolites. The presence of phospholipids and other amphipathic metabolites might enable condensates to facilitate specific metabolic reactions.

Oxygen sensitivity hampers applications of metal-dependent CO₂ reductases. Here, Oliveira et al. describe how an allosteric disulfide bond controls the activity of a CO₂ reductase, preventing its physiological reduction during transient O₂ exposure and allowing aerobic handling of the enzyme.

Controlled interactions between macromolecules are fundamental regulatory layers. Hijacking these circuits via proximity-inducing small molecules offers many therapeutic opportunities. The organizers, Georg Winter and Cristina Mayor-Ruiz, report on the latest trends in this emerging field discussed at the 39th IRB-BioMed Conference in Barcelona.

Cui et al. developed LAUNCHER, a single-component switch using potyviral protease, which offers a high signal-to-noise ratio for precise payload release, enabling versatile cellular applications and enhanced synthetic circuit performance.

Here, the authors describe the mechanistic flexibility and substrate promiscuity of the apramycin resistance enzyme ApmA. They identify additional clinical drugs susceptible to modification through a molecular mechanism that diverges from other enzymes within the left-handed β-helix superfamily.

Dumelie et al. asked whether biomolecular phase-separated condensates can establish microenvironments with distinct metabolomes and found that amphipathic lipids are highly enriched in these microenvironments and influence the properties of the condensates.

Ye et al. reveal the critical role of micropolarity in controlling the structure and miscibility of subcompartments in multiphasic biomolecular condensates, thereby providing new insights into multiphasic condensation regulation.

Terpenoids bearing carbon skeletons derived from nonisoprene units are rare and considered noncanonical. Now, a genome-mining study has uncovered previously unknown noncanonical C₁₆ terpenes and their biosynthetic pathways from bacteria. The findings suggest that noncanonical terpenoids are diverse and widespread in nature.

Development of chemically responsive bandpass filters mimics the signal-processing abilities of electronic circuits in mammalian cells by responding to chemical concentrations within a specific range and rejecting ones outside that range.

Methyl jasmonate in the root volatile organic compounds (rVOCs) signals to the soil microbiome to form biofilms with altered composition that benefits plant growth. This cross-kingdom VOCs-mediated signaling expands the zone of rhizosphere influence.

The integrated stress response affects cell survival or death under stress conditions, and depends on the activity of the eukaryotic translation initiation factor eIF2B. New research identifies a protein helix that modulates this response by controlling the structural states of eIF2B.

A chemical screen identified a small molecule inhibitor of CHEK2 that boosts insulin secretion in human β cells, including those from both healthy and type 2 diabetic human islets, as well as in diabetic mouse models and cynomolgus macaques.

Cofactorless oxygenases are rare in nature and natural product biosynthesis. Here the authors describe the biochemical and structural characterization of two such oxygenases catalyzing deformylation, ring cleavage and epoxidation in the biosynthesis of the enediyne natural product tiancimycin A.

Hydrogen–deuterium exchange–mass spectrometry and cryo-EM analysis revealed an allosteric mechanism involving the conformation of a single α-helix that controls the global conformation and activity of eIF2B, the core molecular machine of the integrated stress response.

The cryo-electron microscopy structure of the GPR101–Gs complex reveals the mechanism for its constitutive activity and facilitates the screening and identification of GPR101 ligands with rejuvenating potential.

Structural analysis of a type III effector protein CteC reveals that it represents a unique ‘D-E’ family of PARP-like ADP-ribosyltransferases, which harbors chimeric features from the enzymes of the R-S-E and H-Y-E classes.

LIS1 is an essential cofactor for the assembly of the cytoplasmic dynein transport machinery. How LIS1 binding affects dynein motility was unclear. Single-molecule experiments reveal that Pac1 (the yeast homolog of LIS1) binding reduces dynein speed by slowing its detachment from microtubules and does not disrupt the mechanism by which it generates force.

Structural analysis of Crenotalea thermophila SPARTA reveals that guide-mediated target binding releases the auto-inhibition of SPARTA imposed by an acidic tail and triggers substantial conformational changes, resulting in the oligomerization of short Ago and TIR for SPARTA activation.

Zhang et al. determine multiple cryo-electron microscopy structures of inactive monomeric and active tetrameric short prokaryotic Ago/TIR–APAZ (SPARTA) complexes, providing structural basis of SPARTA assembly and activation that will facilitate the development of SPARTA-based biotechnological tools.

A yeast platform for de novo biosynthesis of medicinal plant compounds has now been reported. The platform was used to explore the biocatalytic potential of refactored plant pathways and resulted in the production of 19 halogenated derivatives with therapeutic potential.