Cryo-EM characterization of the anydromuropeptide permease AmpG central to bacterial fitness and β-lactam antibiotic resistance.

Bacteria invest significant resources into the continuous creation and tailoring of their essential protective peptidoglycan (PG) cell wall. Several soluble PG biosynthesis products in the periplasm are transported to the cytosol for recycling, leading to enhanced bacterial fitness. GlcNAc-1,6-anhydroMurNAc and peptide variants are transported by the essential major facilitator superfamily importer AmpG in Gram-negative pathogens including Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa.

An alternative broad-specificity pathway for glycan breakdown in bacteria.

The vast majority of glycosidases characterized to date follow one of the variations of the 'Koshland' mechanisms to hydrolyse glycosidic bonds through substitution reactions. Here we describe a large-scale screen of a human gut microbiome metagenomic library using an assay that selectively identifies non-Koshland glycosidase activities. Using this, we identify a cluster of enzymes with extremely broad substrate specificities and thoroughly characterize these, mechanistically and structurally.

Cryo-EM analysis of TarL, a polymerase in wall teichoic acid biogenesis central to virulence and antibiotic resistance.

Wall teichoic acid (WTA), a covalent adduct of Gram-positive bacterial cell wall peptidoglycan, contributes directly to virulence and antibiotic resistance in pathogenic species. Polymerization of the WTA ribitol-phosphate chain is catalyzed by TarL, a member of the largely uncharacterized TagF-like family of membrane-associated enzymes. We report the cryo-electron microscopy structure of TarL, showing a tetramer that forms an extensive membrane-binding platform of monotopic helices.

"I Could Not Talk . . . She Did Everything . . . She's Now My Sister": People With Aphasia's Perspectives on Friends Who Stuck Around.

Purpose: Aphasia may decrease the capacity to develop and maintain friendships. The aim of this study was to better understand the perspectives of people with aphasia on why some friendship bonds remain strong and some do not. Furthermore, we wanted to explore how age and aphasia severity shape views on friendship.

Structural Insights into Type III Secretion Systems of the Bacterial Flagellum and Injectisome.

Two of the most fascinating bacterial nanomachines-the broadly disseminated rotary flagellum at the heart of cellular motility and the eukaryotic cell-puncturing injectisome essential to specific pathogenic species-utilize at their core a conserved export machinery called the type III secretion system (T3SS). The T3SS not only secretes the components that self-assemble into their extracellular appendages but also, in the case of the injectisome, subsequently directly translocates modulating effector proteins from the bacterial cell into the infected host. The injectisome is thought to have evolved from the flagellum as a minimal secretory system lacking motility, with the subsequent acquisition of additional components tailored to its specialized role in manipulating eukaryotic hosts for pathogenic advantage.

A novel class of broad-spectrum active-site-directed 3C-like protease inhibitors with nanomolar antiviral activity against highly immune-evasive SARS-CoV-2 Omicron subvariants.

Antivirals with broad coronavirus activity are important for treating high-risk individuals exposed to the constantly evolving SARS-CoV-2 variants of concern (VOCs) as well as emerging drug-resistant variants. We developed and characterized a novel class of active-site-directed 3-chymotrypsin-like protease (3CLpro) inhibitors (). Our lead direct-acting antiviral (DAA), , is a non-covalent, non-peptide with a dissociation constant of 170 nM against recombinant SARS-CoV-2 3CLpro.

Preventing depression in aphasia: A cluster randomized control trial of the Aphasia Action Success Knowledge (ASK) program.

Background: Stroke patients with aphasia and their caregivers have higher incidence of depression than those without aphasia.

Aims: The objective of the study is to determine whether a tailored intervention program (Action Success Knowledge; ASK) led to better mood and quality of life (QoL) outcomes than an attention control with a 12-month end point at cluster and individual participant level.

Methods: A multi-site, pragmatic, two-level single-blind cluster randomized controlled trial compared ASK to an attention control (secondary stroke prevention program).

Vinyl Halide-Modified Unsaturated Cyclitols are Mechanism-Based Glycosidase Inhibitors.

Suitably configured allyl ethers of unsaturated cyclitols act as substrates of β-glycosidases, reacting via allylic cation transition states. Incorporation of halogens at the vinylic position of these carbasugars, along with an activated leaving group, generates potent inactivators of β-glycosidases. Enzymatic turnover of these halogenated cyclitols (F, Cl, Br) displayed a counter-intuitive trend wherein the most electronegative substituents yielded the most labile pseudo-glycosidic linkages.

An anti-HER2 biparatopic antibody that induces unique HER2 clustering and complement-dependent cytotoxicity.

Human epidermal growth factor receptor 2 (HER2) is a receptor tyrosine kinase that plays an oncogenic role in breast, gastric and other solid tumors. However, anti-HER2 therapies are only currently approved for the treatment of breast and gastric/gastric esophageal junction cancers and treatment resistance remains a problem. Here, we engineer an anti-HER2 IgG1 bispecific, biparatopic antibody (Ab), zanidatamab, with unique and enhanced functionalities compared to both trastuzumab and the combination of trastuzumab plus pertuzumab (tras + pert).

Structural basis of broad-spectrum β-lactam resistance in Staphylococcus aureus.

Broad-spectrum β-lactam antibiotic resistance in Staphylococcus aureus is a global healthcare burden. In clinical strains, resistance is largely controlled by BlaR1, a receptor that senses β-lactams through the acylation of its sensor domain, inducing transmembrane signalling and activation of the cytoplasmic-facing metalloprotease domain. The metalloprotease domain has a role in BlaI derepression, inducing blaZ (β-lactamase PC1) and mecA (β-lactam-resistant cell-wall transpeptidase PBP2a) expression.

Measuring communication as a core outcome in aphasia trials: Results of the ROMA-2 international core outcome set development meeting.

Background: Evidence-based recommendations for a core outcome set (COS; minimum set of outcomes) for aphasia treatment research have been developed (the Research Outcome Measurement in Aphasia-ROMA, COS). Five recommended core outcome constructs: communication, language, quality of life, emotional well-being and patient-reported satisfaction/impact of treatment, were identified through three international consensus studies. Constructs were paired with outcome measurement instruments (OMIs) during an international consensus meeting (ROMA-1).

Pilot trial of the online implementation intervention .

Purpose: is a theoretically-based online implementation intervention designed to overcome the barriers related to the implementation of intensive and comprehensive aphasia services. The objective was to establish the feasibility of incorporating within routine clinical practice through an evaluation of: (1) its potential to positively influence the intensity and/or comprehensiveness of aphasia services; (2) the ability of selected outcome measures to capture changes to factors influencing implementation; and (3) the acceptability of the website to on-site speech-language pathologists (SLPs).

Method: A single arm pre-post pilot trial was conducted within an Australian health service.

A survey of speech pathologists' opinions about the prospective acceptability of an online implementation platform for aphasia services.

Background: Online knowledge translation (KT) approaches are becoming increasingly prevalent within healthcare due to their accessibility and facilitation of international support networks. Online platforms enable timely and far-reaching dissemination of current evidence and best-practice recommendations. Although there is potential to improve the uptake of rehabilitation guidelines, it is essential to consider the acceptability of online approaches to healthcare professionals to ensure their successful integration within everyday clinical settings.

A scoping review of friendship intervention for older adults: lessons for designing intervention for people with aphasia.

Purpose: Map the landscape of friendship interventions/programs for older adults to guide intervention/program development inclusive of the unique needs of older people with aphasia (PWA).

Methods: A search query of multiple databases was completed for articles published before 4 January 2021. Studies included all the following: (1) participants aged 55 years or older; (2) addressed an intervention/program designed to prevent social isolation and/or friendship loss; (3) used an outcome variable related to social isolation and/or friendship; and (4) published in a peer-reviewed journal.

X-ray crystallographic characterization of the SARS-CoV-2 main protease polyprotein cleavage sites essential for viral processing and maturation.

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the pathogen that causes COVID-19, produces polyproteins 1a and 1ab that contain, respectively, 11 or 16 non-structural proteins (nsp). Nsp5 is the main protease (M) responsible for cleavage at eleven positions along these polyproteins, including at its own N- and C-terminal boundaries, representing essential processing events for viral assembly and maturation. Using C-terminally substituted M chimeras, we have determined X-ray crystallographic structures of M in complex with 10 of its 11 viral cleavage sites, bound at full occupancy intermolecularly in trans, within the active site of either the native enzyme and/or a catalytic mutant (C145A).

Access G-AP: development of an accessible goal setting and action planning resource for stroke survivors with aphasia.

Purpose: Goal setting is key to stroke rehabilitation, but access for people with aphasia is challenging. Based on the Goal setting and Action Planning (G-AP) framework, we developed an accessible goal setting resource (Access G-AP).

Methods: Access G-AP was designed using a three-phase, user-centred design process.

Recent structural advances towards understanding of the bacterial type III secretion injectisome.

The bacterial injectisome is a structurally conserved, syringe-shaped nanomachine that spans the Gram-negative envelope and forms a continuous channel for type III secretion of protein effectors. The injectisome, and the host-modulating effectors it secretes, are essential for the pathogenesis of several Gram-negative bacterial species, and it is a key virulence factor associated with the progression of many clinical and community-based infectious diseases. The molecular structure of the injectisome has been the focus of intense research efforts over the past 30 years, and during this time significant progress has been made in determining the molecular structures of many components.

The Hinge Region of the Israeli Acute Paralysis Virus Internal Ribosome Entry Site Directs Ribosomal Positioning, Translational Activity, and Virus Infection.

All viruses must usurp host ribosomes for viral protein synthesis. Dicistroviruses utilize an intergenic region internal ribosome entry site (IGR IRES) to directly recruit ribosomes and mediate translation initiation from a non-AUG start codon. The IGR IRES adopts a three-pseudoknot structure that comprises a ribosome binding domain of pseudoknot II and III (PKII and PKIII), and a tRNA-like anticodon domain (PKI) connected via a short, one to three nucleotide hinge region.

Crystal structure of the Propionibacterium acnes surface sialidase, a drug target for P. acnes-associated diseases.

Propionibacterium acnes, though generally considered part of the normal flora of human skin, is an opportunistic pathogen associated with acne vulgaris as well as other diseases, including endocarditis, endophthalmitis and prosthetic joint infections. Its virulence potential is also supported by knowledge gained from its sequenced genome. Indeed, a vaccine targeting a putative cell wall-anchored P.