PP2A is activated by cytochrome upon formation of a diffuse encounter complex with SET/TAF-Iβ.

Intrinsic protein flexibility is of overwhelming relevance for intermolecular recognition and adaptability of highly dynamic ensemble of complexes, and the phenomenon is essential for the understanding of numerous biological processes. These conformational ensembles-encounter complexes-lack a unique organization, which prevents the determination of well-defined high resolution structures. This is the case for complexes involving the oncoprotein SET/template-activating factor-Iβ (SET/TAF-Iβ), a histone chaperone whose functions and interactions are significantly affected by its intrinsic structural plasticity.

Occurrence, integrity and functionality of AcaML1-like viruses infecting extreme acidophiles of the Acidithiobacillus species complex.

General knowledge on the diversity and biology of microbial viruses infecting bacterial hosts from extreme acidic environments lags behind most other econiches. In this study, we analyse the AcaML1 virus occurrence in the taxon, its genetic composition and infective behaviour under standard acidic and SOS-inducing conditions to assess its integrity and functionality. Occurrence analysis in sequenced acidithiobacilli showed that AcaML1-like proviruses are confined to the mesothermophiles Acidithiobacillus caldus and Thermithiobacillus tepidarius.

The gp27-like Hub of VgrG Serves as Adaptor to Promote Hcp Tube Assembly.

Contractile injection systems are multiprotein complexes that use a spring-like mechanism to deliver effectors into target cells. In addition to using a conserved mechanism, these complexes share a common core known as the tail. The tail comprises an inner tube tipped by a spike, wrapped by a contractile sheath, and assembled onto a baseplate.

Antibacterial Weapons: Targeted Destruction in the Microbiota.

The intestinal microbiota plays an important role in health, particularly in promoting intestinal metabolic capacity and in maturing the immune system. The intestinal microbiota also mediates colonization resistance against pathogenic bacteria, hence protecting the host from infections. In addition, some bacterial pathogens deliver toxins that target phylogenetically related or distinct bacterial species in order to outcompete and establish within the microbiota.

Structure-Function Analysis of the C-Terminal Domain of the Type VI Secretion TssB Tail Sheath Subunit.

The type VI secretion system (T6SS) is a specialized macromolecular complex dedicated to the delivery of protein effectors into both eukaryotic and bacterial cells. The general mechanism of action of the T6SS is similar to the injection of DNA by contractile bacteriophages. The cytoplasmic portion of the T6SS is evolutionarily, structurally and functionally related to the phage tail complex.

Structure-Function Analysis of the TssL Cytoplasmic Domain Reveals a New Interaction between the Type VI Secretion Baseplate and Membrane Complexes.

The type VI secretion system (T6SS) is a multiprotein complex that delivers toxin effectors in both prokaryotic and eukaryotic cells. It is constituted of a long cytoplasmic structure-the tail-made of stacked Hcp hexamers and wrapped by a contractile sheath. Contraction of the sheath propels the inner tube capped by the VgrG spike protein toward the target cell.