Volume 27 Issue 5, May 2020

How Gram-negative bacteria transport glycerophospholipids between membranes remains a major point of inquiry for cell envelope biologists. Two groups report cryo-EM structures and functional studies of LetB (YebT), providing support for its involvement in cell envelope maintenance.

Cryo-EM structures of Escherichia coli ClpAP undergoing active substrate unfolding and proteolysis reveal contacts that drive substrate translocation and a dynamic switch mechanism at the ClpA–ClpP interface.

A cryo-EM structure of a stable, protease-resistant fibril formed by a fragment of the human prion protein shows two intertwined protofilaments with a tightly packed hydrophobic interface.

A combination of cellular and genome-wide mapping approaches reveal that RTEL1 helicase functions with SLX4 to resolve R-loops and G-quadruplex structures that impede DNA replication fork progression in human cells.

Biochemical characterization of the complex formed by tumor suppressor SLX4 and RTEL1 helicase reveals a role in genome integrity maintenance as well as how their interaction is impaired by disease-associated mutations.

In vitro reconstitution of translesion synthesis–mediated replication fork restart shows how DNA Pol η is recruited to bypass a CPD lesion on the leading strand in the context of the yeast replisome.

In vitro assays using a fully reconstituted DNA replication system reveal that the checkpoint kinase Rad53 restrains CMG helicase activity to prevent DNA unwinding and collapse of stalled forks in response to replication stress.

Crystal structures, MD simulations and functional analyses of CRY2 and CRY2:BIC2 complexes from Arabidopsis reveal how BIC2 inhibits CRY2 photoactivation by reducing proton and electron transfer rates upon photoreduction and by disrupting CRY2 oligomers to generate inactive monomers.

Structural determination and analysis of the PHR domain of plant CRY proteins suggest that blue-light perception causes the CRY oligomerization required for downstream signaling.

Single-molecule FRET analysis of EfaCas1−Cas2 integrase establishes the kinetic framework for CRISPR spacer acquisition and shows that transcription effictively resolves the postsynaptic complex to ensure efficient and directional spacer integration.

CDK11 functions with histone pre-mRNA-processing factor FLASH to upregulate expression of replication-dependent histone genes in S phase and to couple transcription and processing of nascent histone transcripts in mammalian cells.