Volume 2 Issue 6, June 2017

We asked microbiologist and NASA astronaut Kate Rubins about her time on the International Space Station, the challenges of working with bugs in space, and what's next for science that is out of this world.

It is unclear why pregnant women are at high risk of severe influenza infection. Allogeneic pregnancy in mice is now shown to alter both innate and adaptive responses to influenza virus infection, enabling the emergence of more virulent virus variants.

Structural and functional studies of the archaeum Methanocaldococcus jannaschii Argonaute (MjAgo) reveal a DNA-guided DNA nuclease that is also active without a guide. This unguided activity is suggested to prime MjAgo for its subsequent sequence-specific DNA-silencing role in host defence.

The antimalarial mefloquine has been used in the clinic for decades, yet its mode of action has remained elusive. Now, a study reports that the enantiomer (+)-mefloquine binds to the cytosolic ribosome of the major malaria parasite Plasmodium falciparum.

Structural analysis of the mycobacterial ESX-5 secretion complex presents an important step towards understanding how the ESX type VII (T7) secretion systems can translocate a multitude of substrates — including virulence factors involved in pathogenesis — across the bacterial cell envelope.

Flaviviruses stimulate cross-reactive immune responses that may reduce or exacerbate manifestations of subsequent flavivirus infection. Recent work demonstrates that cross-reactive T cells protect against Zika in HLA transgenic mice, a key step in the development of safe and effective vaccines.

This Review Article examines how microorganisms that have key roles in the ocean carbon and nitrogen cycles may respond to anthropogenic changes in the Earth's marine ecosystems.

In this Perspective, Suez and Elinav describe the potential for therapeutic approaches based on the use of metabolites secreted, modulated or degraded by the gut microbiome, and issues that will be critical for their implementation.

Cyclic di-GMP signalling leads to lipopolysaccharide modification and reduced inflammatory response during Pseudomonas aeruginosa infection.

Bioinformatics analysis identifies 900 encapsulin nanocompartments in prokaryotes that are associated with cargo proteins carrying out diverse functions.

Cryo-EM reveals one mechanism of action of the antimalarial mefloquine: mefloquine binds to the Plasmodium falciparum 80S ribosome, inhibiting protein synthesis in the parasite.

Trypanosoma brucei, which is responsible for human sleeping sickness, has an intrinsic circadian clock that regulates metabolism and influences drug sensitivity.

The Plasmodium falciparum telomere repeat-binding zinc finger protein (PfTRZ) binds telomeres, subtelomeric var genes and 5S ribosomal DNA genes. PfTRZ regulates multiple processes in the parasite, including telomere length homeostasis and cell cycle progression.

ZIKV-specific and ZIKV/DENV cross-reactive human HLA epitopes are identified in naïve and DENV-immune mice, revealing altered immunodominance in the DENV-immune setting and a protective role for epitope-specific CD8⁺ T cells against ZIKV.

In addition to canonical guide-dependent endonuclease activity, the Argonaute protein from the archaeon Methanocaldococcus jannaschii (MjAgo) is capable of guide-independent DNA cleavage, enabling MjAgo to process plasmids and genomic DNA.

Crystal structures of the Argonaute protein from the archaeon Methanocaldococcus jannaschii (MjAgo) in its apo state and bound to a guide DNA elucidate the molecular mechanisms that drive DNA-guided DNA silencing in Archaea.

Comparative genomics of 24 Penicillium species, including 9 that are newly sequenced, characterizes over 1000 secondary metabolism gene clusters, some of which are validated experimentally, identifying these fungi as an important untapped source of bioactive compounds.

Diversity-generating retroelements are abundant in the reduced genomes of bacteria and archaea belonging to the CPR and DPANN phyla, driving hypervariability on proteins involved in signalling, transcriptional regulation, attachment and defence.

Single-particle analysis of electron microscopy structures elucidates the mycobacterial ESX-5 type VII secretion system membrane complex.

Drosophila Bap180 is induced by immune deficiency/Relish in response to both pathogenic and commensal bacteria. Bap180 can feedback to restrain immune deficiency signalling and repress pro-inflammatory gene eiger (TNF), limiting tissue damage and elongating life span.