Is a Malleable Active Site Loop the Key to High Substrate Promiscuity? Hybrid, Biocatalytic Route to Structurally Diverse Taxoid Side Chains with Remarkable Dual Stereocontrol.

These studies reveal the first structure of Clostridium acetobutylicum alcohol dehydrogenase (CaADH), a protein exhibiting remarkable substrate promiscuity and stereochemical fidelity. The CaADH enzyme is utilized here for synthesizing 20 potential aryl isoserine side chains for the Taxotere family of tubulin-binding chemotherapeutics. The approach involves dynamic reductive kinetic resolution (DYRKR) upon the corresponding α-chloro-β-keto esters, showing high D-syn stereoselectivity, including those leading to the clinically relevant milataxel (Ar = 2-furyl) and simotaxel (Ar = 2-thienyl) side chains.

Drug-Gene Interactions and Clinical Outcomes After Vascular Surgery in the Million Veteran Program.

Importance: Pharmacogenetics can improve medication-related outcomes by optimizing efficacy and minimizing adverse effects. It is unknown whether the presence of drug-gene interactions (DGIs) at the time of surgery results in adverse outcomes in the postoperative setting.

Objective: To determine the association of active DGIs on postsurgical outcomes following vascular surgery procedures.

Insight into the Conformational Ensembles Formed by U-U and T-T Mismatches in RNA and DNA Duplexes From a Structure-based Survey, NMR, and Molecular Dynamics Simulations.

Nucleic acid base pairs interconvert between alternative conformations on a free energy landscape, and these dynamics play critical roles in recognition, folding, and catalysis. U-U and T-T mismatches can adopt two nearly isoenergetic wobble conformations, distinguished by their relative shearing displacements. Experimental NMR evidence suggests that these conformations dynamically interconvert in RNA motifs containing tandem U-U mismatches.

Determination of Thiol Protonation States by Sulfur X-ray Spectroscopy in Biological Systems.

Cysteine is one of the most functionally diverse of the proteinogenic amino acids, owing to its reactive thiol side chain that can undergo deprotonation to form a strongly nucleophilic thiolate. However, few techniques can directly interrogate sulfur charge and covalency in cysteine, particularly in proteins. X-ray spectroscopies provide an element specific probe of sulfur.

Development and use of DJ-1 affinity microcolumns to screen and study small drug candidates for Parkinson's disease.

Background: DJ-1 is a protein whose mutation causes rare heritable forms of Parkinson's disease (PD) and is of interest as a target for treating PD and other disorders. This work used high performance affinity microcolumns to screen and examine the binding of small molecules to DJ-1, as could be used to develop new therapeutics or to study the role of DJ-1 in PD. Non-covalent entrapment was used to place microgram quantities of DJ-1 in an unmodified form within microcolumns, which were then used in multiple studies to analyze binding by model compounds and possible drug candidates to DJ-1.

Access to Evaluation for Liver Transplantation in the Veterans Health Administration.

Background: As the largest US provider of cirrhosis care, the Veterans Health Administration (VA) is the ideal setting to assess patient-, clinician-, and site-level barriers to transplant evaluation.

Aims: To assess barriers to transplant evaluation referral among Veterans with cirrhosis or hepatocellular carcinoma (HCC).

Methods: Logistic regression assessed facility, patient, clinical, and distance factors associated with transplant referral for Veterans with cirrhosis or HCC, over 1 year.

Scaling and merging time-resolved pink-beam diffraction with variational inference.

Time-resolved x-ray crystallography (TR-X) at synchrotrons and free electron lasers is a promising technique for recording dynamics of molecules at atomic resolution. While experimental methods for TR-X have proliferated and matured, data analysis is often difficult. Extracting small, time-dependent changes in signal is frequently a bottleneck for practitioners.

Scaling and Merging Time-Resolved Laue Data with Variational Inference.

Time-resolved X-ray crystallography (TR-X) at synchrotrons and free electron lasers is a promising technique for recording dynamics of molecules at atomic resolution. While experimental methods for TR-X have proliferated and matured, data analysis is often difficult. Extracting small, time-dependent changes in signal is frequently a bottleneck for practitioners.

IRG1/ACOD1 promotes neutrophil reverse migration and alleviates local inflammation.

Polymorphonuclear neutrophil (PMN) infiltration at inflammatory site plays a critical role in inflammation. PMN reverse migration (rM) describes the phenomenon that PMNs migrate away from inflammatory site back into the vasculature, and its role within inflammatory scenarios remains to be fully determined. This study aimed to investigate the mechanism underlying PMN rM and its role in inflammation.

Patient Surgical Outcomes When Surgery Residents Are the Primary Surgeon by Intensity of Surgical Attending Supervision in Veterans Affairs Medical Centers.

Objective: Using health records from the Department of Veterans Affairs (VA), the largest healthcare training platform in the United States, we estimated independent associations between the intensity of attending supervision of surgical residents and 30-day postoperation patient outcomes.

Background: Academic leaders do not agree on the level of autonomy from supervision to grant surgery residents to best prepare them to enter independent practice without risking patient outcomes.

Methods: Secondary data came from a national, systematic 1:8 sample of n = 862,425 teaching encounters where residents were listed as primary surgeon at 122 VA medical centers from July 1, 2004, through September 30, 2019.

X-ray-driven chemistry and conformational heterogeneity in atomic resolution crystal structures of bacterial dihydrofolate reductases.

Dihydrofolate reductase (DHFR) catalyzes the NADPH-dependent reduction of dihydrofolate to tetrahydrofolate. Bacterial DHFRs are targets of several important antibiotics as well as model enzymes for the role of protein conformational dynamics in enzyme catalysis. We collected 0.

Changes in an Enzyme Ensemble During Catalysis Observed by High Resolution XFEL Crystallography.

Enzymes populate ensembles of structures with intrinsically different catalytic proficiencies that are difficult to experimentally characterize. We use time-resolved mix-and-inject serial crystallography (MISC) at an X-ray free electron laser (XFEL) to observe catalysis in a designed mutant (G150T) isocyanide hydratase (ICH) enzyme that enhances sampling of important minor conformations. The active site exists in a mixture of conformations and formation of the thioimidate catalytic intermediate selects for catalytically competent substates.

A molecular device for the redox quality control of GroEL/ES substrates.

Hsp60 chaperonins and their Hsp10 cofactors assist protein folding in all living cells, constituting the paradigmatic example of molecular chaperones. Despite extensive investigations of their structure and mechanism, crucial questions regarding how these chaperonins promote folding remain unsolved. Here, we report that the bacterial Hsp60 chaperonin GroEL forms a stable, functionally relevant complex with the chaperedoxin CnoX, a protein combining a chaperone and a redox function.

Understanding Cysteine Chemistry Using Conventional and Serial X-Ray Protein Crystallography.

Proteins that use cysteine residues for catalysis or regulation are widely distributed and intensively studied, with many biomedically important examples. Enzymes where cysteine is a catalytic nucleophile typically generate covalent catalytic intermediates whose structures are important for understanding mechanism and for designing targeted inhibitors. The formation of catalytic intermediates can change enzyme conformational dynamics, sometimes activating protein motions that are important for catalytic turnover.

Bryozoan-cnidarian mutualism triggered a new strategy for greater resource exploitation as early as the Late Silurian.

Bryozoans were common benthic invertebrates in the Silurian seas. The large biodiversity among Silurian benthic organisms prompted diversified interactions, and as a result bryozoans hosted many other organisms as symbionts. Here we analyse the cystoporate bryozoan Fistulipora przhidolensis and unidentified trepostomes intergrown with auloporid tabulate corals and putative hydrozoans.

Divergent evolution of extreme production of variant plant monounsaturated fatty acids.

Metabolic extremes provide opportunities to understand enzymatic and metabolic plasticity and biotechnological tools for novel biomaterial production. We discovered that seed oils of many species contain up to 92% of the unusual monounsaturated petroselinic acid (18:1Δ6), one of the highest reported levels for a single fatty acid in plants. Supporting the biosynthetic origin of petroselinic acid, we identified a Δ6-stearoyl-acyl carrier protein (18:0-ACP) desaturase from , closely related to a previously identified Δ6-palmitoyl-ACP desaturase that produces sapienic acid (16:1Δ6)-rich oils in seeds.

Metabolite Damage and Damage Control in a Minimal Genome.

Analysis of the genes retained in the minimized JCVI-Syn3A genome established that systems that repair or preempt metabolite damage are essential to life. Several genes known to have such functions were identified and experimentally validated, including 5-formyltetrahydrofolate cycloligase, coenzyme A (CoA) disulfide reductase, and certain hydrolases. Furthermore, we discovered that an enigmatic YqeK hydrolase domain fused to NadD has a novel proofreading function in NAD synthesis and could double as a MutT-like sanitizing enzyme for the nucleotide pool.

Timing of a Major Operative Intervention After a Positive COVID-19 Test Affects Postoperative Mortality: Results From a Nationwide, Procedure-matched Analysis.

Background: Studies indicate that coronavirus disease 2019 (COVID-19) infection before or soon after operations increases mortality, but they do not comment on the appropriate timing for interventions after diagnosis.

Objective: We sought to determine what the safest time would be for COVID-19 diagnosed patients to undergo major operative interventions.

Methods: High-risk operations, between January 2020 and May 2021, were identified from the Veterans Affairs COVID-19 Shared Data Resource.

EWALD: A macromolecular diffractometer for the second target station.

Revealing the positions of all the atoms in large macromolecules is powerful but only possible with neutron macromolecular crystallography (NMC). Neutrons provide a sensitive and gentle probe for the direct detection of protonation states at near-physiological temperatures and clean of artifacts caused by x rays or electrons. Currently, NMC use is restricted by the requirement for large crystal volumes even at state-of-the-art instruments such as the macromolecular neutron diffractometer at the Spallation Neutron Source.

DJ-1 is not a deglycase and makes a modest contribution to cellular defense against methylglyoxal damage in neurons.

Human DJ-1 is a cytoprotective protein whose absence causes Parkinson's disease and is also associated with other diseases. DJ-1 has an established role as a redox-regulated protein that defends against oxidative stress and mitochondrial dysfunction. Multiple studies have suggested that DJ-1 is also a protein/nucleic acid deglycase that plays a key role in the repair of glycation damage caused by methylglyoxal (MG), a reactive α-keto aldehyde formed by central metabolism.