PilY1 regulates the dynamic architecture of the type IV pilus machine in Pseudomonas aeruginosa.

Type IV pili (T4P) produced by the pathogen Pseudomonas aeruginosa play a pivotal role in adhesion, surface motility, biofilm formation, and infection in humans. Despite the significance of T4P as a potential therapeutic target, key details of their dynamic assembly and underlying molecular mechanisms of pilus extension and retraction remain elusive, primarily due to challenges in isolating intact T4P machines from the bacterial cell envelope. Here, we combine cryo-electron tomography with subtomogram averaging and integrative modelling to resolve in-situ architectural details of the dynamic T4P machine in P.

Self-evolutionary recycling of flame-retardant polyurethane foam enabled by controllable catalytic cleavage.

Polyurethane (PU) foams, pivotal in modern life, face challenges suh as fire hazards and environmental waste burdens. The current reliance of PU on potentially ecotoxic halogen-/phosphorus-based flame retardants impedes large-scale material recycling. Here, our demonstrated controllable catalytic cracking strategy, using cesium salts, enables self-evolving recycling of flame-retardant PU.

The effect of charge and albumin on cellular uptake of supramolecular polymer nanostructures.

Intracellular delivery of functional biomolecules by using supramolecular polymer nanostructures has gained significant interest. Here, various charged supramolecular ureido-pyrimidinone (UPy)-aggregates were designed and formulated a simple "mix-and-match" method. The cellular internalization of these UPy-aggregates in the presence or absence of serum proteins by phagocytic and non-phagocytic cells, , THP-1 derived macrophages and immortalized human kidney cells (HK-2 cells), was systematically investigated.

A pleiotropic role of sialidase in the pathogenicity of .

As one of the keystone pathogens of periodontitis, the oral bacterium produces an array of virulence factors, including a recently identified sialidase (PG0352). Our previous report involving loss-of-function studies indicated that PG0352 plays an important role in the pathophysiology of . However, this report had not been corroborated by gain-of-function studies or substantiated in different strains.

Genome-wide identification of B-box zinc finger (BBX) gene family in Medicago sativa and their roles in abiotic stress responses.

Background: B-box (BBX) family is a class of zinc finger transcription factors (TFs) that play essential roles in regulating plant growth, development, as well as abiotic stress. However, no systematic analysis of BBX genes has yet been conducted in alfalfa (Medica go sativa L.), and their functions have not been elucidated up to now.

Outer membrane vesicles and the outer membrane protein OmpU govern biofilm matrix assembly.

Biofilms are matrix-encased microbial communities that increase the environmental fitness and infectivity of many human pathogens including . Biofilm matrix assembly is essential for biofilm formation and function. Known components of the biofilm matrix are the polysaccharide polysaccharide (VPS), matrix proteins RbmA, RbmC, Bap1, and extracellular DNA, but the majority of the protein composition is uncharacterized.

Ice nucleation proteins self-assemble into large fibres to trigger freezing at near 0 °C.

In nature, frost can form at a few degrees below 0 °C. However, this process requires the assembly of tens of thousands of ice-like water molecules that align together to initiate freezing at these relatively high temperatures. Water ordering on this scale is mediated by the ice nucleation proteins (INPs) of common environmental bacteria like and .

A peptide-binding domain shared with an Antarctic bacterium facilitates human cell binding and intestinal colonization.

the causative agent of the disease cholera, is responsible for multiple pandemics. binds to and colonizes the gastrointestinal tract within the human host, as well as various surfaces in the marine environment (e.g.

Ice nucleation proteins self-assemble into large fibres to trigger freezing at near 0 °C.

In nature, frost can form at a few degrees below 0 °C. However, this process requires the assembly of tens of thousands of ice-like water molecules that align together to initiate freezing at these relatively high temperatures. Water ordering on this scale is mediated by the ice nucleation proteins of common environmental bacteria like and .

Exogenous Proline Improves Salt Tolerance of Alfalfa through Modulation of Antioxidant Capacity, Ion Homeostasis, and Proline Metabolism.

Alfalfa ( L.) is an important forage crop, and its productivity is severely affected by salt stress. Although proline is a compatible osmolyte that plays an important role in regulating plant abiotic stress resistance, the basic mechanism of proline requires further clarification regarding the effect of proline in mitigating the harmful effects of salinity.

The Bacterial Flagellar Motor: Insights Into Torque Generation, Rotational Switching, and Mechanosensing.

The flagellar motor is a bidirectional rotary nanomachine used by many bacteria to sense and move through environments of varying complexity. The bidirectional rotation of the motor is governed by interactions between the inner membrane-associated stator units and the C-ring in the cytoplasm. In this review, we take a structural biology perspective to discuss the distinct conformations of the stator complex and the C-ring that regulate bacterial motility by switching rotational direction between the clockwise (CW) and counterclockwise (CCW) senses.

FliL ring enhances the function of periplasmic flagella.

SignificanceHow flagella sense complex environments and control bacterial motility remain fascinating questions. Here, we deploy cryo-electron tomography to determine in situ structures of the flagellar motor in wild-type and mutant cells of , revealing that three flagellar proteins (FliL, MotA, and MotB) form a unique supramolecular complex in situ. Importantly, FliL not only enhances motor function by forming a ring around the stator complex MotA/MotB in its extended, active conformation but also facilitates assembly of the stator complex around the motor.

Molecular basis for inhibition of adhesin-mediated bacterial-host interactions through a peptide-binding domain.

Infections typically begin with pathogens adhering to host cells. For bacteria, this adhesion can occur through specific ligand-binding domains. We identify a 20-kDa peptide-binding domain (PBD) in a 1.

Structural Basis of Ligand Selectivity by a Bacterial Adhesin Lectin Involved in Multispecies Biofilm Formation.

Carbohydrate recognition by lectins governs critical host-microbe interactions. PA14 ( PA14 domain) lectin is a domain of a 1.5-MDa adhesin responsible for a symbiotic bacterium-diatom interaction in Antarctica.

Enhancing the Freeze-Thaw Durability of Concrete through Ice Recrystallization Inhibition by Poly(vinyl alcohol).

Frost weathering of porous materials caused by seasonal temperature changes is a major source of damage to the world's infrastructure and cultural heritage. Here we investigate poly(vinyl alcohol) (PVA) addition as a means to enhance the freeze-thaw durability of concrete without compromising its structural or mechanical integrity. We evaluate the ice recrystallization inhibition activity of PVA in a cementitious environment and the impact of PVA on key structural and mechanical properties, such as cement hydration (products), microstructure, strength, as well as freeze-thaw resistance.

Engineered Living Materials Based on Adhesin-Mediated Trapping of Programmable Cells.

Engineered living materials have the potential for wide-ranging applications such as biosensing and treatment of diseases. Programmable cells provide the functional basis for living materials; however, their release into the environment raises numerous biosafety concerns. Current designs that limit the release of genetically engineered cells typically involve the fabrication of multilayer hybrid materials with submicrometer porous matrices.

Correction: Structure and functional analysis of a bacterial adhesin sugar-binding domain.

[This corrects the article DOI: 10.1371/journal.pone.

Structure and functional analysis of a bacterial adhesin sugar-binding domain.

Bacterial adhesins attach their hosts to surfaces through one or more ligand-binding domains. In RTX adhesins, which are localized to the outer membrane of many Gram-negative bacteria via the type I secretion system, we see several examples of a putative sugar-binding domain. Here we have recombinantly expressed one such ~20-kDa domain from the ~340-kDa adhesin found in Marinobacter hydrocarbonoclasticus, an oil-degrading bacterium.

Phasing with calcium at home.

With better tools for data processing and with synchrotron beamlines that are capable of collecting data at longer wavelengths, sulfur-based native single-wavelength anomalous dispersion (SAD) phasing has become the `first-choice' method for de novo protein structure determination. However, for many proteins native SAD phasing can be simplified by taking advantage of their interactions with natural metal cofactors that are stronger anomalous scatterers than sulfur. This is demonstrated here for four unique domains of a 1.