Articles in 2017

RNA-DamID, a novel approach to detect lncRNA–genome interactions in vivo with high sensitivity and accuracy, demonstrates that the initial targeting of lncRNAs in the Drosophila dosage-compensation complex is cell-type specific.

The APOBEC-AID family of cytidine deaminases target single-stranded nucleic acids for cytidine-to-uridine deamination and can thereby affect DNA repair processes that occur during CRISPR–Cas9-mediated genome editing.

Heterozygous cancer-associated SMARCA4 missense mutations disrupt conserved ATPase surfaces of this chromatin remodeler and alter the open chromatin landscape, thus inducing pro-oncogenic gene expression.

Cryo-EM structures of nucleosomes in partially unwrapped, transient states reveal intrinsic plasticity that is required for nucleosome stability and can be exploited by chromatin-remodeling factors.

Real-time FRET analyses and biochemical assays reveal that Rad51 recombinase promotes DNA strand exchange via two distinct three-strand intermediate states.

The cryo-EM structure of the human INO80 chromatin-remodeling complex reveals the architecture of the complex centered around a RUVBL1–2 AAA+ heterohexamer.

Deadenylation of mRNAs is generally associated with translational inhibition and mRNA decay. A study now reports that, unexpectedly, highly expressed genes tend to have shorter poly(A) tails and suggests that poly(A) tails can be 'pruned', generating a 30-nucleotide-biased phased distribution, likely due to protection by poly(A)-binding proteins.

The helicase intrinsic to DNA polymerase θ (Polθ), the versatile mediator of microhomology-based repair of DNA double-strand breaks and stalled replication forks, is now revealed to be a member of an elite group of proteins known as annealing helicases. This small family of enzymes remodels DNA intermediates in multiple repair processes that are crucial to preserving genome stability and warding off cancer and aging.

The crystal structure of an oligosaccharyltransferase in complex with a sugar donor and an acceptor peptide provides insight into the mechanism of protein glycosylation and reveals how lipid-linked oligosaccharides are positioned in the enzyme active site.

The mechanics and mechanisms of ribosomal translocation, including the conformational rearrangements in the ribosome and the roles of EF-G and tRNAs, are discussed in this Perspective by Mohan, Noller and colleagues.

In this Review, the authors consider how single-molecule biophysical approaches can inform our understanding of the ring-shaped structural maintenance of chromosome (SMC) complexes and their function in chromosome organization.

Ultrastructural analysis of nuclear membrane topology and assembling NPCs reveals how mitotic cells can rapidly establish a closed nuclear compartment while at the same time making it transport competent.

Apolipoprotein A-I (apoA-I) is the scaffold protein that is essential for the assembly and function of HDL particles. A structural model for monomeric, lipid-free apoA-I, based on previous and new data, is now presented.

Asynchronous replication-timing patterns undergo programmed switching between maternal and paternal alleles in embryonic and adult stem cells.

The cGAS-STING cytoplasmic-DNA-sensing pathway is activated by accumulation of extrachromosomal telomere repeats, and this proliferation-inhibition mechanism is defective in ALT cancer cells.

During transcription initiation, Ssl2, the dsDNA translocase of TFIIH, opens a 6-bp DNA bubble, suggesting a two-step model wherein Ssl2 triggers a 6-bp open complex that RNA polymerase II expands via NTP-dependent RNA transcription.

Although deadenylation induces translational inhibition and mRNA decay, well-expressed transcripts are now shown to possess short, well-defined poly(A) tails, suggesting that pruned tails may be ideal for protective and translational functions.

Cryo-EM analyses of human TRPML3 reveal this channel in three different states—closed, agonist-activated and low-pH-inhibited—and suggest mechanisms for regulation.

Assembly of the small ribosomal subunit from an RNA strand and 33 proteins is an intricate and dynamic process. Two cryo-EM studies now provide insight into a complicated complex of at least 51 trans-factors that act on the preribosomal small subunit to sequentially fold it into a 3D molecular machine.

Engineering an LCK mutant, in which an active-site lysine is replaced by a photocaged equivalent via genetic code expansion, allows quantitation of phosphorylation kinetics in situ and provides insights into LCK activation dynamics.