Volume 534 Number 7605

Editorials

Toxic control p.5

The United States is overhauling its chemicals law; now it must tackle carbon emissions.

doi: 10.1038/534005b

Dark satanic wings p.5

Just as the dark-coloured pepper moth disappears from northern England, researchers are finally getting to the bottom of how it gained its colour.

doi: 10.1038/534005a

Seeing farther p.6

Our fascination with telescopes and the worlds they reveal spreads beyond science into culture.

doi: 10.1038/534006a

News

News Features

News & Views

Pluto's polygons explained p.40

The Sputnik Planum basin of Pluto contains a sheet of nitrogen ice, the surface of which is divided into irregular polygons tens of kilometres across. Two studies reveal that vigorous convection causes these polygons. See Letters p.79 & 82

doi: 10.1038/534040a

Pumping persisters p.41

The finding that antibiotics are pumped out of drug-tolerant bacterial cells by the TolC protein complex provides insight into how some cells, known as persisters, survive in the face of antibiotic treatments.

doi: 10.1038/nature18442

A photo shoot of plant photosystem II p.42

In photosynthesis, the plant photosystem II uses the energy in sunlight to oxidize water. The high-resolution structure of this crucial supercomplex has now been obtained using cryo-electron microscopy. See Article p.69

doi: 10.1038/nature18438

Neanderthals built underground p.43

The finding of 175,000-year-old structures deep inside a cave in France suggests that Neanderthals ventured underground and were responsible for some of the earliest constructions made by hominins. See Letter p.111

doi: 10.1038/nature18440

Earth's core problem p.45

Measurements of the electrical resistance and thermal conductivity of iron at extreme pressures and temperatures cast fresh light on controversial numerical simulations of the properties of Earth's outer core. See Letters p.95 & 99

doi: 10.1038/534045a

Articles

Landscape of somatic mutations in 560 breast cancer whole-genome sequences p.47

Whole-genome sequencing of tumours from 560 breast cancer cases provides a comprehensive genome-wide view of recurrent somatic mutations and mutation frequencies across both protein coding and non-coding regions; several mutational signatures in these cancer genomes are associated with BRCA1 or BRCA2 function and defective homologous-recombination-based DNA repair.

doi: 10.1038/nature17676

Proteogenomics connects somatic mutations to signalling in breast cancer p.55

Quantitative mass-spectrometry-based proteomic and phosphoproteomic analyses of genomically annotated human breast cancer samples elucidates functional consequences of somatic mutations, narrows candidate nominations for driver genes within large deletions and amplified regions, and identifies potential therapeutic targets.

doi: 10.1038/nature18003

Letters

Attosecond nonlinear polarization and light–matter energy transfer in solids p.86

Electric-field-induced charge separation (polarization) is the most fundamental manifestation of the interaction of light with matter and a phenomenon of great technological relevance. Nonlinear optical polarization produces coherent radiation in spectral ranges inaccessible by lasers and constitutes the key to ultimate-speed signal manipulation. Terahertz techniques have provided experimental access to this important observable up to frequencies of several terahertz. Here we demonstrate that attosecond metrology extends the resolution to petahertz frequencies of visible light. Attosecond polarization spectroscopy allows measurement of the response of the electronic system of silica to strong (more than one volt per ångström) few-cycle optical (about 750 nanometres) fields. Our proof-of-concept study provides time-resolved insight into the attosecond nonlinear polarization and the light–matter energy transfer dynamics behind the optical Kerr effect and multi-photon absorption. Timing the nonlinear polarization relative to the driving laser electric field with sub-30-attosecond accuracy yields direct quantitative access to both the reversible and irreversible energy exchange between visible–infrared light and electrons. Quantitative determination of dissipation within a signal manipulation cycle of only a few femtoseconds duration (by measurement and ab initio calculation) reveals the feasibility of dielectric optical switching at clock rates above 100 terahertz. The observed sub-femtosecond rise of energy transfer from the field to the material (for a peak electric field strength exceeding 2.5 volts per ångström) in turn indicates the viability of petahertz-bandwidth metrology with a solid-state device.

doi: 10.1038/nature17650

Oil sands operations as a large source of secondary organic aerosols p.91

The evaporation and atmospheric oxidation of low-volatility organic vapours from mined oil sands material is shown to be responsible for a large amount of secondary organic aerosol mass—which affects air quality and climate change—observed during airborne measurements in Canada.

doi: 10.1038/nature17646

Diverse roles of assembly factors revealed by structures of late nuclear pre-60S ribosomes p.133

Ribosome biogenesis is a highly complex process in eukaryotes, involving temporally and spatially regulated ribosomal protein (r-protein) binding and ribosomal RNA remodelling events in the nucleolus, nucleoplasm and cytoplasm. Hundreds of assembly factors, organized into sequential functional groups, facilitate and guide the maturation process into productive assembly branches in and across different cellular compartments. However, the precise mechanisms by which these assembly factors function are largely unknown. Here we use cryo-electron microscopy to characterize the structures of yeast nucleoplasmic pre-60S particles affinity-purified using the epitope-tagged assembly factor Nog2. Our data pinpoint the locations and determine the structures of over 20 assembly factors, which are enriched in two areas: an arc region extending from the central protuberance to the polypeptide tunnel exit, and the domain including the internal transcribed spacer 2 (ITS2) that separates 5.8S and 25S ribosomal RNAs. In particular, two regulatory GTPases, Nog2 and Nog1, act as hub proteins to interact with multiple, distant assembly factors and functional ribosomal RNA elements, manifesting their critical roles in structural remodelling checkpoints and nuclear export. Moreover, our snapshots of compositionally and structurally different pre-60S intermediates provide essential mechanistic details for three major remodelling events before nuclear export: rotation of the 5S ribonucleoprotein, construction of the active centre and ITS2 removal. The rich structural information in our structures provides a framework to dissect molecular roles of diverse assembly factors in eukaryotic ribosome assembly.

doi: 10.1038/nature17942