SOS1 is a guanine nucleotide exchange factor that promotes KRAS activation by catalyzing GDP release and GTP loading, making SOS1-mediated nucleotide exchange an attractive therapeutic target in KRAS-driven cancers. Herein, we report the synthesis, biophysical characterization, and structural analysis of aminobenzo-[d]-isothiazole 1,1-dioxide SOS1 ligands. Compound 6f engaged SOS1 with a KD of 570 nM by microscale thermophoresis, supported by surface plasmon resonance. X-ray crystal structures of SOS1 bound to compounds 6b and 6f refined previous binding hypotheses regarding pocket engagement. Rather than being dominated by sulfone-mediated contacts, SOS1 recognition is primarily driven by hydrophobic and aromatic packing within the canonical pocket, a conserved ligand NH hydrogen bond to Asn879, and π-π stacking with Tyr884, recapitulating key features of BI-3406 binding. Comparative analysis further delineates vector requirements for productive engagement of KRAS-facing regions, providing a structure-based framework for future optimization of aminobenzo-[d]-isothiazole 1,1-dioxide SOS1 ligands.

The SARS-CoV-2 main protease (3CLpro) is a well-validated target for structure-guided inhibitor discovery. Here, we report α-aminomethyl tetrazole inhibitors accessed via the Ugi tetrazole multicomponent reaction (UT-4CR), enabling rapid exploration of non-classical chemical space. Initial design and modeling suggested a binding mode analogous to Ugi-derived (U-4CR) 3CLpro inhibitors, with heteroaromatic substituents engaging the S1 pocket. However, crystallographic analysis revealed an unexpected binding orientation in which the tetrazole core itself occupies the S1 pocket and forms the key interaction with His163, while the modeled substituents are solvent-exposed. This revised binding mode rationalizes the observed structure-activity relationships. Installation of an electrophilic warhead yielded covalent inhibitors with sub-micromolar enzymatic potency, and lead compound 2a displayed modest antiviral activity in infected cells. These results highlight UT-4CR-derived tetrazoles as a platform for probing the 3CLpro binding space and underscore the importance of early crystallographic validation.

SOS1 is a guanine nucleotide exchange factor that promotes KRAS activation by catalyzing GDP release and GTP loading, making SOS1-mediated nucleotide exchange an attractive therapeutic target in KRAS-driven cancers. Herein, we report the synthesis, biophysical characterization, and structural analysis of aminobenzo[d]isothiazole 1,1-dioxide SOS1 ligands. Compound 6f engaged SOS1 with a K-D of 570 nM by microscale thermophoresis, supported by surface plasmon resonance. X-ray crystal structures of SOS1 bound to compounds 6b and 6f refined previous binding hypotheses regarding pocket engagement. Rather than being dominated by sulfone-mediated contacts, SOS1 recognition is primarily driven by hydrophobic and aromatic packing within the canonical pocket, a conserved ligand NH hydrogen bond to Asn879, and pi-pi stacking with Tyr884, recapitulating key features of BI-3406 binding. Comparative analysis further delineates vector requirements for productive engagement of KRAS-facing regions, providing a structure-based framework for future optimization of aminobenzo[d]isothiazole 1,1-dioxide SOS1 ligands

Victorian courts have long held family hardship arising from sentences of imprisonment must be exceptional for it to be considered an ‘aggravating or mitigating factor’ within the scope of s 5(2)(g) of the Sentencing Act 1991 (Vic). This approach arose without reference to the Charter of Human Rights and Responsibilities Act 2006 (Vic) (‘Victorian Charter’) and the interaction between the Charter and sentencing legislation remains neglected. However, that interaction will be considered before the High Court of Australia in Charisiou v The King (‘Charisiou’). Charisiou could be decided in several ways. One is to modify the judicially implied requirement that family circumstances must be exceptional to attract s 5(2)(g). This path would not necessarily require recourse to the Victorian Charter. The second path is the one adopted by Walker JA in dissent in the Victorian Court of Appeal: that the family rights protected by the Victorian Charter could inform the scope of s 5(2)(g). Both paths could consider the consequence, if any, of the lack of amendment to s 5(2)(g). Does that reflect an acceptance of existing judicial principles? Is such an assumption affected by the interpretive requirements of the Victorian Charter? If these questions are resolved with significant recourse to the Charter, the consequences of Charisiou may extend far beyond the realm of sentencing.

2-quinolones are privileged scaffolds for drug discovery that are relatively rare in nature. Here, we characterise two promiscuous fungal polyketide synthases AthePKS and FerePKS, which we had previously found to produce quinolones in vitro. We challenged the enzymes with several substituted anthranilic acid derivatives, revealing their ability to produce precursors of pharmaceutically relevant quinolones. We also discovered that AthePKS and FerePKS accept other 2-substituted benzoic acids, leading to the formation of coumarin and thiocoumarin scaffolds. We applied AthePKS in an artificial enzymatic cascade towards an antimicrobial 4-methoxy-1-methyl-2-quinolone and demonstrated its in vivo feasibility by successfully expressing the pathway in Escherichia coli . Lastly, we determined the crystal structure of AthePKS, suggesting hotspots for enhancing its catalytic efficiency by enzyme engineering. Our results provide a framework for further engineering of enzymatic routes towards privileged heteroaromatic scaffolds and derivatives thereof. ### Competing Interest Statement The authors have declared no competing interest.

Politicians are regarded as unreliable and untruthful, largely because their actions do not match their words. There can be good reasons for politicians to change their mind or resile from earlier public statements, such as changed circumstances or a sudden crisis. But there are good reasons why elected officials should honour their prior statements. One is integrity. Public confidence in government will be improved if politicians are seen as likely to honour their word. Requirements of integrity can pull the other way. The bias rule requires decision-makers to approach tasks with an appropriate level of impartiality, but this creates a tension for politicians. The rule requires them to approach issues without strongly preconceived views or prejudgment, yet making statements and promises about future conduct is the lifeblood of politics. This article examines how the courts balance those issues and argues that the bias rule is applied to politicians in a weak manner that offers no real judicial oversight.

The office of Attorney-General is an ancient one that remains central to the legal system. The Attorney-General exercises many functions and powers important to the legal system but is also a politician and member of cabinet. This article explains the key functions of the Attorney-General and also the political position of that officer. The focus of the article is upon federal law. It also examines three federal Attorneys-General of modern times and considers how their actions have influenced or reflected the changing conceptions of that office. The article does not suggest that changing conceptions of the office are either good or bad, but instead that they are a reality. The article suggests that these changes provide a reason to reconsider some of the traditional privileges of the Attorney-General, such as the power to grant a fiat in judicial review claims and the Attorney’s privileged position in standing for judicial review of administrative action.

The Commonwealth Administrative Review Tribunal (ART) commenced operation on 14 October 2024. The new ART replaces the Administrative Appeals Tribunal (AAT), which operated for almost 50 years. In many ways, the ART appears to replace and continue the AAT but a close inspection reveals that the new tribunal is much more than a rebranding of the one it replaces. The ART represents a far-reaching reform of the federal tribunal system. The ART legislation introduces many structural and procedural innovations that will significantly change merits review at the federal level. The establishment of the AAT led the states and territories to mimic and build upon the innovations of the Commonwealth. If the same is true of the ART, the new Commonwealth tribunal may spark considerable reform in other jurisdictions. This article explains key innovations contained in the Administrative Review Tribunal Act 2024 (Cth) and those key concepts developed under the previous legislation which will continue. The article also details the different mechanisms built into the new ART which are aimed to create an environment of continuous oversight and reform.

Aspartate transcarbamoylase (ATC) is the first committed step in de novo pyrimidine biosynthesis in eukaryotes and plants. A potent transition state analog of human ATCase (PALA) has previously been assessed in clinical trials for the treatment of cancer, but was ultimately unsuccessful. Additionally, inhibition of this pathway has been proposed to be a target to suppress cell proliferation in E. coli, the malarial parasite and tuberculosis. In this manuscript we screened a 70-member library of ATC inhibitors developed against the malarial and tubercular ATCases for inhibitors of the human ATC. Four compounds showed low nanomolar inhibition (IC50 30-120 nM) in an in vitro activity assay. These compounds significantly outperform PALA, which has a triphasic inhibition response under identical conditions, in which significant activity remains at PALA concentrations above 10 μM. Evidence for a druggable allosteric pocket in human ATC is provided by both in vitro enzyme kinetic, homology modeling and in silico docking. These compounds also suppress the proliferation of U2OS osteoblastoma cells by promoting cell cycle arrest in G0/G1 phase. This report provides the first evidence for an allosteric pocket in human ATC, which greatly enhances its druggability and demonstrates the potential of this series in cancer therapy.

Plasmodium falciparum is the main causative agent of malaria, a deadly disease that mainly affects children under five years old. Artemisinin-based combination therapies have been pivotal in controlling the disease, but resistance has arisen in various regions, increasing the risk of treatment failure. The non-mevalonate pathway is essential for the isoprenoid synthesis in Plasmodium and provides several under-explored targets to be used in the discovery of new antimalarials. 1-deoxy-D-xylulose-5-phosphate synthase (DXPS) is the first and rate-limiting enzyme of the pathway. Despite its importance, there are no structures available for any Plasmodium spp., due to the complex sequence which contains large regions of high disorder, making crystallisation a difficult task. In this manuscript, we use cryo-electron microscopy to solve the P. falciparum DXPS structure at a final resolution of 2.42 Å. Overall, the structure resembles other DXPS enzymes but includes a distinct N-terminal domain exclusive to the Plasmodium genus. Mutational studies show that destabilization of the cap domain interface negatively impacts protein stability and activity. Additionally, a density for the co-factor thiamine diphosphate is found in the active site. Our work highlights the potential of cryo-EM to obtain structures of P. falciparum proteins that are unfeasible by means of crystallography. DXPS is an important enzyme for isoprenoid synthesis in Plasmodium falciparum. Here, authors elucidate the cryo-EM structure of PfDXPS showing an N-terminal domain only present in this genus. Mutation studies show its importance in DXPS stability and activity.

The Administrative Review Tribunal Act 2023 (Cth) contains provisions to establish a new version of the Administrative Review Council (ARC). The ARC was established under the Administrative Appeals Tribunal Act 1975 (Cth) and was long an important aspect of our administrative law framework. The ARC remains a part of the Administrative Appeals Tribunal legislation but the Council has been inactive for many years. The article explains the original purpose of the ARC, how it fell into slumber and the functions and potential value of a revived ARC. The article argues that the newly formed ARC may be stronger than its previous incarnation.

Stagnation in the development of new antibiotics emphasizes the need for the discovery of drugs with novel modes of action that can tackle antibiotic resistance. Contrary to humans, most bacteria use the methylerythritol phosphate (MEP) pathway to synthesize crucial isoprenoid precursors. 1-deoxy-D-xylulose 5-phosphate synthase (DXPS) catalyzes the first and rate-limiting step of the pathway, making it an attractive target. Alkylacetylphosphonates (alkylAPs) are a class of pyruvate mimicking DXPS inhibitors that react with thiamin diphosphate (ThDP) to form a stable phosphonolactyl (PLThDP) adduct. Here, we present the first M. tuberculosis DXPS crystal structure in complex with an inhibitor (butylacetylphosphonate (BAP)) using a construct with improved crystallization properties. The 1.6 Å structure shows that the BAP adduct interacts with catalytically important His40 and several other conserved residues of the active site. In addition, a glycerol molecule, present in the D-glyceraldehyde 3-phosphate (D-GAP) binding site and within 4 Å of the BAP adduct, indicates that there is space to extend and develop more potent alkylAPs. The structure reveals the BAP binding mode and provides insights for enhancing the activity of alkylAPs against M. tuberculosis, aiding in the development of novel antibiotics.

The enzyme Thiosulfate sulfurtransferase (TST, EC 2.8.1.1), is a positive genetic predictor of diabetes type 2 and obesity. As increased TST activity protects against the development of diabetic symptoms in mice, an activating compound for TST may provide therapeutic benefits in diabetes and obesity. We identified a small molecule activator of human TST through screening of an inhouse small molecule library. Kinetic studies in vitro suggest that two distinct isomers of the compound are required for full activation as well as an allosteric mode of activation. Additionally, we studied the effect of TST protein and the activator on TST activity through mitochondrial respiration. Molecular docking and molecular dynamics (MD) approaches supports an allosteric site for the binding of the activator, which is supported by the lack of activation in the Escherichia coli. mercaptopyruvate sulfurtransferase. Finally, we show that increasing TST activity in isolated mitochondria increases mitochondrial oxygen consumption.

In AB v Independent Broad -Based Anti -Corruption Commission , the High Court of Australia will consider the level of disclosure that the rules of fairness require an investigative body to observe when finalising a draft report. The central issue is the tension between the duty to provide adverse material (enough for an affected person to have a fair chance to respond) and the need for the investigator to withhold some material (enough for it to still be able to discharge its function). This question has arisen as a narrow one of construction under s 162(3) of the Independent Broad -Based Anti -Corruption Commission Act 2011 (Vic), but it raises the age-old dilemma of the rules of fairness - how to protect the interests of someone who may be adversely affected by administrative action without unduly impairing the functions of the officials responsible for that action. This column argues that the dilemma may not be able to be resolved beyond the statement of broad principles.

Hydrogen-deuterium exchange mass spectrometry (HDX-MS) is a method to probe the solvent accessibility and conformational dynamics of a protein or a protein-ligand complex with respect to exchangeable amide hydrogens. Here, we present the application of HDX-MS to determine the binding sites of Affimer reagents to the monoclonal antibodies trastuzumab and pertuzumab, respectively. Intact and subunit level HDX-MS analysis of antibody-affimer complexes showed significant protection from HDX in the antibody Fab region upon affimer binding. Bottom-up HDX-MS experiments including online pepsin digestion revealed that the binding sites of the affimer reagents were mainly located in the complementarity-determining region (CDR) 2 of the heavy chain of the respective antibodies. Three-dimensional models of the binding interaction between the affimer reagents and the antibodies were built by homology modeling and molecular docking based on the HDX data.

Fragment-based approaches offer rapid screening of chemical space and have become a mainstay in drug discovery. This manuscript provides a recent example that highlights the initial and intermediate stages involved in the fragment-based discovery of an allosteric inhibitor of the malarial aspartate transcarbamoylase (ATCase), subsequently shown to be a potential novel anti-malarial. The initial availability of high-resolution diffracting crystals allowed the collection of a number of protein fragment complexes, which were then assessed for inhibitory activity in an in vitro assay, and binding was assessed using biophysical techniques. Elaboration of these compounds in cycles of structure-based drug design improved activity and selectivity between the malarial and human ATCases. A key element in this process was the use of multicomponent reaction chemistry as a multicomponent compatible fragment library, which allowed the rapid generation of elaborated compounds, the rapid construction of a large (70 member) chemical library, and thereby efficient exploration of chemical space around the fragment hits. This review article details the steps along the pathway of the development of this library, highlighting potential limitations of the approach and serving as an example of the power of combining multicomponent reaction chemistry with fragment-based approaches.

Thiosulfate sulfurtransferase (TST, EC 2.8.1.1) was discovered as an enzyme that detoxifies cyanide by conversion to thiocyanate (rhodanide) using thiosulfate as substrate; this rhodanese activity was subsequently identified to be almost exclusively located in mitochondria. More recently, the emphasis regarding its function has shifted to hydrogen sulfide metabolism, antioxidant defense, and mitochondrial function in the context of protective biological processes against oxidative distress. While TST has been described to play an important role in liver and colon, its function in the brain remains obscure. In the present study, we therefore sought to address its potential involvement in maintaining cerebral redox balance in a murine model of global TST deficiency (Tst-/- mice), primarily focusing on characterizing the biochemical phenotype of TST loss in relation to neuronal activity and sensitivity to oxidative stress under basal conditions. Here, we show that TST deficiency is associated with a perturbation of the reactive species interactome in the brain cortex secondary to altered ROS and RSS (specifically, polysulfide) generation as well as mitochondrial OXPHOS remodeling. These changes were accompanied by aberrant Nrf2-Keap1 expression and thiol-dependent antioxidant function. Upon challenging mice with the redox-active herbicide paraquat (25 mg/kg i.p. for 24 h), Tst-/- mice displayed a lower antioxidant capacity compared to wildtype controls (C57BL/6J mice). These results provide a first glimpse into the molecular and metabolic changes of TST deficiency in the brain and suggest that pathophysiological conditions associated with aberrant TST expression and/or activity renders neurons more susceptible to oxidative stress-related malfunction.