Research articles

A toxic conformation of disease-linked huntingtin protein with expanded polyQ is degraded more slowly than the other conformations, as it is less able to engage the autophagy machinery, explaining its higher toxicity compared to other conformations.

Identification of the antibiotic peptide KLB, from Klebsiella pneumoniae, which inhibits the growth of various Gram-negative bacteria by binding the nascent peptide exit tunnel on the large ribosomal subunit in a compact curled conformation, thereby stalling translation.

Lytic polysaccharide monooxygenases (LPMOs) catalyze the oxidative cleavage of polysaccharides. Identification of a hydrogen peroxide–dependent pathway for sugar oxidation by these enzymes challenges the prevailing model that LPMOs are oxygen-dependent monooxygenases.

A combination of bulk and single-molecule FRET, as well as cleavage activity assays, reveals that the twister ribozyme requires more Mg²⁺ for folding than it does for self-cleavage, and is also more efficiently activated by several transition metals.

Crystal structures of the HIV-1 Env trimer with cell-entry inhibitor antiviral drug leads BMS-378806 and BMS-626529 along with biophysical data define allosteric and competitive mechanisms to inhibit CD4-induced structural changes in Env.

The development of two new optogenetic dimerizers—CTH, which promoted uncaging with less light and longer wavelengths, and TNH, a reversible dimerizer—enabled spatial and temporal manipulation of kinetochore-mediated checkpoint signaling and transport of chromosomes to the spindle equator.

Inhibitors of CDK8 enhance IL-10 production during innate immune activation in human and mouse primary macrophages and dendritic cells via diminished phosphorylation of the c-Jun subunit of the AP-1 transcription regulatory complex.

Bisphosphoglycerate mutase (BPGM) drives phosphoglycerate mutase 1 (PGAM1) phosphorylation, which is required for glycolytic flux. Loss of BPGM is partially compensated by 1,3-BPG directly phosphorylating PGAM1, sustaining glycolytic flux but diverting metabolites for serine synthesis.

A nonribosomal peptide synthetase involved in colibactin biosynthesis utilizes S-adenosylmethionine as a nonproteinogenic amino acid building block, which is then converted into the cyclopropane moiety that is critical for colibactin's genotoxic activity.

Structure-guided engineering of an NADH oxidase switches its cofactor preference, thus yielding an NADPH oxidase that can be used to tune the cellular NADP⁺/NADPH ratio and to examine the links between mitochondrial NADH and NADPH pools.

Biochemical characterization and mutagenesis of Trt14 with a series of substrate and intermediate analogs, plus structural analysis of Trt14 and two homologs, reveal how the enzyme catalyzes D-ring rearrangement during meroterpenoid biosynthesis.

The pyrophosphate analog imidodiphosphate (PNP) alters the reaction equilibrium of human DNA polymerase β, and the resulting increase in the rate of pyrophosphorolysis enables kinetic and structural dissection of this reverse reaction of the enzyme.

Under high-copper conditions, yersiniabactin (Ybt) binds copper (Cu) to prevent toxicity. Ybt is now shown to mediate Cu import under low-Cu conditions through formation of a Cu(II)-Ybt complex resulting in metalation of a Cu-requiring enzyme.

Biophysical and structural analyses reveal how the glycosylase AlkD utilizes a mechanism of excision that does not involve base flipping to enable an alternative repair pathway for large yatakemycin–DNA adducts.

Profiling of over 13,000 compounds against yeast gene deletion mutants, defining the differential responses on cells, reveals chemical-genetic interactions that can be used to predict compound function and their target pathways.

Adenomatous polyposis coli (APC) is shown to promote colorectal cancer cell migration by activating the guanine nucleotide exchange factor Asef. Structure-based design resulted in the development of peptidomimetic inhibitors that disrupted APC–Asef interactions.

FRET sensors based on the adenylation and peptidyl carrier protein domains of a nonribosomal peptide synthetase illuminate the relationships between conformational dynamics and the catalytic cycle of this multidomain assembly line enzyme.

Structural characterization of carboxylic acid reductase in multiple didomain configurations, coupled with mutagenesis, reveals how the enzyme transitions into a catalytically competent orientation and prevents over-reduction of its aldehyde product.

The use of chemical exchange saturation transfer NMR reveals a previously hidden excited conformational state of the fluoride riboswitch, providing a model in which ligand binding allosterically suppresses a linchpin base pair to activate transcription.

The structure of vanadium nitrogenase reveals key differences from its counterpart molybdenum nitrogenase, particularly in the way it ligands its FeV cofactor, that help to explain the basis for the unique properties of these two nitrogenases.