217 articles from THURSDAY 3.10.2019

Active site rearrangement and structural divergence in prokaryotic respiratory oxidases

Cytochrome bd–type quinol oxidases catalyze the reduction of molecular oxygen to water in the respiratory chain of many human-pathogenic bacteria. They are structurally unrelated to mitochondrial cytochrome c oxidases and are therefore a prime target for the development of antimicrobial drugs. We determined the structure of the Escherichia coli cytochrome bd-I oxidase by single-particle...

Cryo-EM structure of a dimeric B-Raf:14-3-3 complex reveals asymmetry in the active sites of B-Raf kinases

Raf kinases are important cancer drug targets. Paradoxically, many B-Raf inhibitors induce the activation of Raf kinases. Cryo–electron microscopy structural analysis of a phosphorylated B-Raf kinase domain dimer in complex with dimeric 14-3-3, at a resolution of ~3.9 angstroms, shows an asymmetric arrangement in which one kinase is in a canonical "active" conformation. The distal segment of...

Decline of the North American avifauna

Species extinctions have defined the global biodiversity crisis, but extinction begins with loss in abundance of individuals that can result in compositional and functional changes of ecosystems. Using multiple and independent monitoring networks, we report population losses across much of the North American avifauna over 48 years, including once-common species and from most biomes. Integration of...

Differential soil fungus accumulation and density dependence of trees in a subtropical forest

The mechanisms underlying interspecific variation in conspecific negative density dependence (CNDD) are poorly understood. Using a multilevel modeling approach, we combined long-term seedling demographic data from a subtropical forest plot with soil fungal community data by means of DNA sequencing to address the feedback of various guilds of soil fungi on the density dependence of trees. We show...

Evolution of vocal learning and spoken language

Although language, and therefore spoken language or speech, is often considered unique to humans, the past several decades have seen a surge in nonhuman animal studies that inform us about human spoken language. Here, I present a modern, evolution-based synthesis of these studies, from behavioral to molecular levels of analyses. Among the key concepts drawn are that components of spoken language...

From speech and talkers to the social world: The neural processing of human spoken language

Human speech perception is a paradigm example of the complexity of human linguistic processing; however, it is also the dominant way of expressing vocal identity and is critically important for social interactions. Here, I review the ways that the speech, the talker, and the social nature of speech interact and how this may be computed in the human brain, using models and approaches from nonhuman...

Gas filaments of the cosmic web located around active galaxies in a protocluster

Cosmological simulations predict that the Universe contains a network of intergalactic gas filaments, within which galaxies form and evolve. However, the faintness of any emission from these filaments has limited tests of this prediction. We report the detection of rest-frame ultraviolet Lyman-α radiation from multiple filaments extending more than one megaparsec between galaxies within the...

Gas flow and accretion via spiral streamers and circumstellar disks in a young binary protostar

The majority of stars are part of gravitationally bound stellar systems, such as binaries. Observations of protobinary systems constrain the conditions that lead to stellar multiplicity and subsequent orbital evolution. We report high–angular resolution observations of the circumbinary disk around [BHB2007] 11, a young binary protostar system. The two protostars are embedded in circumstellar...