Volume 4 Issue 11, November 2019

12,13-diHOME produced by the gut microbiome promotes an asthma-like immunophenotype in the lungs of a murine experimental model. Accordingly, the metabolite is elevated in neonates who developed asthma during childhood, potentially providing a biomarker for early risk prediction and a novel therapeutic target.

Some RNAs have to be made at maximal achievable rates, yet RNA polymerase encounters many obstacles that slow it down. A new study shows that a group of co-transcribing RNA polymerases communicate over long distances to work more efficiently than a solo enzyme.

A statistical analysis of the associations between virus structure and virus transmission suggests that virus structures limit viral transmission routes and have implications for infection prophylaxis and gene therapy strategies.

A combination of secondary structure probing and RNA crosslinking sequencing approaches sheds lights on the RNA conformations and the intra- and intersegment interactions of the genome inside influenza A virions.

Using metatranscriptomics of diatom-associated viruses and quantification of extracellular viruses in coastal water samples, the authors link silicon limitation to increased virus-induced mortality of diatoms, which could have implications for marine biogeochemical cycling.

The cryo-electron microscopy structure of the ribosome from the microsporidium Vairimorpha necatrix reveals that, despite extreme genome compaction reducing the ribosomal RNA to a functionally conserved core, most ribosomal proteins are retained and adapt to form the minimized protein synthesis machinery in these eukaryotic parasites.

The use of nanobodies that inhibit the self-assembly of the S-layer protein Sap from B. anthracis enabled the elucidation of the structure of this protein. The nanobodies also trigger disintegration of assembled S-layers and attenuate both bacterial growth and anthrax pathology in animal models of infection.

Bacterial dimethylsulfoniopropionate (DMSP) production was recently demonstrated in surface oceans. Here the authors show that bacterial production is higher in sediment from coastal areas and the deep ocean, and identify an alternative pathway for its synthesis, indicating that coastal and marine sediments are important sources of this climate-relevant metabolite.

Here, the authors apply quantitative microbiome profiling to a metagenomics data set comprising patients with primary sclerosing cholangitis and/or inflammatory bowel disease and identify microbial taxa associated with inflammation or specific disease indicators, which were validated in an independent inflammatory bowel disease cohort.

Whole-genome resequencing and genome-wide association studies identify host candidate genes that influence the ability of the biocontrol agent Wolbachia to reduce dengue virus replication in its mosquito vector Aades aegypti.

The host protein Transportin-1 is a co-factor of HIV-1 infection, binding to the viral capsid to regulate the release of the viral genome and promoting its nuclear import.

Elevated concentrations of the lipid 12,13-diHOME in neonatal faeces is associated with childhood atopy and asthma. Here, the authors identify bacterial epoxide hydrolase genes that produce this lipid, are more abundant in the gut microbiota of neonates who develop atopy and/or asthma and are associated with diminished immune tolerance.

Phylogenetic reconciliation traces the evolution of glycopeptide antibiotic biosynthesis gene clusters from pre-existing gene pools to 150–400 million years ago; resistance to these antibiotics also arose contemporaneously.

The ADP-ribosyltransferase PARP11 promotes ubiquitination and degradation of the interferon type I (IFN-I) receptor IFNAR1 by mono-ADP-ribosylating the ubiquitin E3 ligase β-TrCP, thus suppressing the IFN-I-mediated antiviral responses both in vitro and in vivo.

Cryo-electron microscopy structures of the antifeeding prophage AFP from Serratia entomophila elucidate the interactions between the different components of this multiprotein contractile injection system and provide insights into its mechanism of contraction and toxin delivery.

A machine learning approach was used to recover over 10,000 inovirus-like sequences from existing microbial genomes and metagenomes, consequently proposing the reclassification of the Inoviridae family to a viral order, and uncover the previously unrecognized diversity of these viruses across hosts and environments.

A sequencing method that enables simultaneous determination of both 5′ and 3′ ends of cellular transcripts, SEnd-seq, reveals a more complex picture of transcription in E. coli, including the existence of multiple overlapping bidirectional terminators that regulate the efficiency of transcription termination.

Genomic and epidemiological analysis of carbapenem-resistant Klebsiella pneumoniae across Europe finds increased transmissibility of four clonal lineages, especially between hospitals within countries.

In a mouse model of influenza virus infection, inflammatory dendritic cells are recruited to the infected trachea. Their activation through the C-type lectin receptor SIGN-R1 stimulates recruitment of natural killer cells and contributes to the control of viral replication.

Phylogeographical genomic analysis of Neisseria gonorrhoeae uncovers its recent emergence and current distribution into two distinct lineages that are differentially associated with antibiotic resistance and sexual networks.

The parasite Toxoplasma gondii secretes a virulence factor, the kinase ROP17 that modulates Rho–ROCK signalling in the infected host cell, enhancing monocyte motility on the surface of endothelial cells and inhibiting transmigration across endothelial barriers.

Survival of epithelial club cells to influenza A virus infection depends on the ability of the DNA mismatch repair pathway to repair virus-induced oxidative damage and to promote the transcriptional induction of host antiviral genes.

Magnetotactic bacteria must assemble magnetosomes into a linear chain that orients the cell along magnetic fields, yet how spiral bacteria with highly curved surfaces accomplish this is unclear. Here, MamY is shown to assemble into linear structures that serve as a scaffold for magnetosomes in magnetotactic spirilla.

Small-angle X-ray scattering and crystal structures of the PA28 proteasome regulator from Plasmodium falciparum, combined with cryo-electron microscopy structures of the 20S proteasome in complex with these regulatory PA28 proteins and molecular dynamics simulations, elucidate the regulatory mechanisms of parasite proteasome degradation.

Shigella flexneri aerobic respiration depletes mucosal oxygen in the colon to promote infection.

Cryo-EM imaging of the needle complex of the SPI-1 type III secretion system from Salmonella enterica serovar Typhimurium at different stages of complex assembly elucidates how needle assembly initiation is regulated and how the inner membrane and outer membrane rings of the complex interact, even with apparently incompatible symmetries.