Volume 28 Issue 1, January 2021

How can structural biology help us understand and combat SARS-CoV-2? Researchers in the field share their experiences and opinions and point to the challenges that lie ahead.

The multisubunit phospholipid transport system Mla has been under scrutiny to determine whether it functions as an exporter or an importer. Structural studies accompanied by the reconstitution of the entire Mla system into proteoliposomes now reveal that ATP binding and hydrolysis drive phospholipid import.

The protein SARM1 is an executioner of axon degeneration through its NAD⁺ hydrolase activity. Three groups now report structures of human SARM1 in an inactive state and identify NAD⁺ as an allosteric inhibitor, illuminating an elegant mechanism of how SARM1 is activated at lower NAD⁺ levels and causes NAD⁺ collapse and axon degeneration.

A new cryo-EM structure of human DNA-PKcs in complex with a Ku70/80 heterodimer and DNA reveals how Ku80–DNA-PKcs interactions create a scaffold to mediate DNA double-strand break repair.

Cryo-EM analyses of the reconstituted radial spoke head and neck from Chlamydomonas reveal a rigid structure with an acidic surface, well-suited for communication with the microtubule central pair, and provide insight into human ciliopathies.

Cryo-EM structures of radial spokes and nexin−dynein regulatory complex (N-DRC) attached to doublet microtubules isolated from Chlamydomonas reinhardtii provide a model for mechanoregulation of motile cilia.

Ultra-low-input native ChIP-seq analyses of genome-wide histone H3.3 distribution during early mouse development reveal a CAF-1-dependent transition from a non-canonical pattern in the oocyte and zygote to a canonical distribution at the two-cell stage.

Cryo-EM structures and functional analyses of wild-type and constitutively active Mec1–Ddc2 complexes reveal the basis of Mec1 kinase activation and how Dpb11 stimulates Mec1 activity.

TET2 promotes the conversion of 5-methylcytosine to 5-hydroxymethylcytosine on tRNAs and affects the processing or stability of different classes of tRNA fragments.

Cryo-EM and biochemical analyses of a subcomplex of S. cerevisiae RSC comprising its ATPase Sth1, Arp7, Arp9 and Rtt102 show that large conformational changes are part of Sth1 regulation and advance a mechanistic understanding of RSC complex assembly.

Cryo-EM structures, along with transport assays with proteoliposomes and bacterial growth analyses, show that the Escherichia coli Mla complex mediates ATP-dependent retrograde transport of phospholipids.

Biochemical and structural characterization of the meiotic DSB core complex of budding yeast reveals molecular architecture and DNA-binding properties similar to those of ancestral Topo VI.

Denaturing CLIP analyses and functional assays in mouse ESCs reveal that PRC2 interacts with nascent transcripts via specific RNA motifs to promote POL-II pausing and to control transcription elongation within non-canonical PRC2 gene targets.