UBXD1 cracks the p97 ring open

A study from Braxton et al. reports how the UBXD1 adapter remodels and opens the hexamer ring of p97/VCP, revealing its regulatory role.

See Braxton et al.

SCARF: start codon-associated ribosomal frameshifting

A study from the Qian laboratory reports ribosomal frameshifting events occurring shortly after start codon selection, which they term ‘start codon-associated ribosomal frameshifting (SCARF).’ These events increase translational ‘noise’ and are increased in response to nutrient starvation.

See Mao et al.

Single-molecule chromatin fibers coming into focus

A study from the Narlikar and Ramani labs presents SAMOSA-ChAAT, a method for resolving how chromatin-interacting proteins restructure individual chromatin fibers in high-throughput and at scale.

See Abdulhay, Hsieh, McNally, Ostrowski et al.

Mapping uncharted waters in antibiotic–ribosome interactions

A study by Paternoga et al. presents high-resolution structures of 17 antibiotics bound to Escherichia coli ribosomes, thus unveiling conserved antibiotic binding to the ribosome, including ordered water molecules.

See Paternoga et al.

X-chromosome inactivation: insights from the active and inactive X chromosome

Three studies published in Nature Structural & Molecular Biology this month investigate the molecular mechanisms of dosage compensation in mammals. Collombet et al. find that during initiation of X-chromosome inactivation, Xist-driven compartmentalization of heterochromatin does not sequester transcribing RNA polymerase II. Poonperm et al. provide molecular insight into how the inactive X chromosome is reorganized to be replicated in late S phase. Rücklé et al. show that active X-derived transcripts appear to be less decorated with m6A and are more stable than autosomal mRNAs.

See Collombet et al. , Poonperm et al. and Rücklé et al.

A Cascade in the energy landscape of crRNA loop formation

A study by Kauert et al. delineates how the Cascade effector complex regulates the energy landscape of R-loop formation between CRISPR RNA (crRNA) and DNA target strands.

See Kauert et al.

Protecting the sister chromatids at centromeres

A study by García-Nieto et al. shows that SGO1 bears the responsibility of protecting centromeric cohesin from WAPL-mediated unloading until the kinetochore and the microtubules have formed functional attachments.

See García-Nieto et al.

Anterograde intraflagellar transport trains

Using a combination of cryo-electron tomography and structure prediction approaches, Lacey et al. reveal the molecular structure of IFT-A and IFT-B trains, providing insights into anterograde transport of cargo into the cilia tip.

See Lacey et al.

Adipokine leptin-induced receptor assembly

Structural studies reveal how adipokine leptin induces trimerization of the leptin receptor in the hypothalamus to convey cellular signaling through the resulting cytokine–receptor assembly.

See Tsirigotaki et al.

PRPS1 assembles for allosteric activation

A series of cryo-EM structures elucidate the function of PRPS1 filament formation from D3 symmetric hexamers, which stabilizes allosteric sites within the enzyme and promotes its activation.

See Hvorecny et al.

Regulation of Cas7-11 by TPR-CHAT

The CRISPR-guided nuclease Cas7-11 forms a bird-like Craspase complex with the regulatory protease TPR-CHAT.

See Ekundayo et al.

A single rRNA modification gates ribosome assembly

A single 2′-O-methylation of ribosomal RNA gates the assembly of a functional ribosome.

See Yelland et al.