A dissected non-ribosomal peptide synthetase maintains activity.

Non-ribosomal peptide synthetases (NRPSs) generate chemically complex compounds and their modular architecture suggests that changing their domain organization can predictably alter their products. Ebony, a small three-domain NRPS, catalyzes the formation of β-alanine containing amides from biogenic amines. To examine the necessity of interdomain interactions, we modeled and docked domains of Ebony to reveal potential interfaces between them.

Persistent anxiety among high school students: Survey results from the second year of the COVID pandemic.

Introduction: National mental health surveys have demonstrated increased stress and depressive symptoms among high-school students during the first year of the COVID-19 pandemic, but objective measures of anxiety after the first year of the pandemic are lacking.

Methods: A 25-question survey including demographics, the Generalized Anxiety Disorder-7 scale (GAD-7) a validated self-administered tool to evaluate anxiety severity, and questions on achievement goals and future aspirations was designed by investigators. Over a 2-month period, all students from grade 9-12 in a single high-school (n = 546) were invited to complete an online survey after electronic parental consent and student assent.

Cobamide remodeling.

Cobamides are a family of structurally-diverse cofactors which includes vitamin B and over a dozen natural analogs. Within the nucleotide loop structure, cobamide analogs have variable lower ligands that fall into three categories: benzimidazoles, purines, and phenols. The range of cobamide analogs that can be utilized by an organism is dependent on the specificity of its cobamide-dependent enzymes, and most bacteria are able to utilize multiple analogs but not all.

A commensal-encoded genotoxin drives restriction of colonization and host gut microbiome remodeling.

SignificanceIn a polymicrobial battlefield where different species compete for nutrients and colonization niches, antimicrobial compounds are the sword and shield of commensal microbes in competition with invading pathogens and each other. The identification of an -produced genotoxin, colibactin, and its specific targeted killing of enteric pathogens and commensals, including and , sheds light on our understanding of intermicrobial interactions in the mammalian gut. Our findings elucidate the mechanisms through which genotoxins shape microbial communities and provide a platform for probing the larger role of enteric multibacterial interactions regarding infection and disease outcomes.

Escherichia coli Nissle 1917 secondary metabolism: aryl polyene biosynthesis and phosphopantetheinyl transferase crosstalk.

Escherichia coli Nissle 1917 (EcN) is a Gram-negative bacterium that is used to treat inflammatory bowel diseases. The probiotic character of EcN is not well-understood, but its ability to produce secondary metabolites plays an important role in its activity. The EcN genome encodes for an aryl polyene (APE) biosynthetic gene cluster (BGC), and APE products have a role in biofilm formation.

California and Oregon NICU Wildfire Disaster Preparedness Tools.

The 2020 wildfire season was devastating to the Western United States and affected the region's NICUs. In this study, we ask the question, "what tools/strategies do medical professionals deem as important and most helpful as they are preparing for wildfire disaster response?" It is a follow up to our previous study: Learning from Wildfire Disaster Experience in California NICUs. We reevaluated how California NICUs dealt with the 2020 wildfires and expanded to Oregon and Southwest (SW) Washington NICUs.

Direct Cobamide Remodeling via Additional Function of Cobamide Biosynthesis Protein CobS from Vibrio cholerae.

Vitamin B belongs to a family of structurally diverse cofactors with over a dozen natural analogs, collectively referred to as cobamides. Most bacteria encode cobamide-dependent enzymes, many of which can only utilize a subset of cobamide analogs. Some bacteria employ a mechanism called cobamide remodeling, a process in which cobamides are converted into other analogs to ensure that compatible cobamides are available in the cell.

Delivery room oxygen physiology and respiratory interventions for newborns with cyanotic congenital heart disease.

Objective: To characterize pulse oxygen saturation (SpO) trajectories and respiratory interventions after birth for newborns with cyanotic congenital heart disease (CCHD).

Study Design: Retrospective single-site study of newborns ≥32 weeks gestation with CCHD: single ventricle with critical aortic obstruction (SV-CAO), critical pulmonic obstruction (CPO), transposition of the great arteries (TGA). Minute-to-minute SpO values and respiratory interventions were summarized and compared.

Learning from Wildfire Disaster Experience in California NICUs.

Wildfires have been affecting California greatly, and vulnerable patients in neonatal intensive care units (NICUs) are not exempt. Our aim was to learn how personnel working in NICUs of California hospitals handled issues of neonatal transfer during wildfire disasters in recent years, with an ultimate goal to share lessons learned with healthcare teams on disaster preparedness. We identified California fires through newspaper articles and the CalFire.

Epithelial Migration and Non-adhesive Periderm Are Required for Digit Separation during Mammalian Development.

The fusion of digits or toes, syndactyly, can be part of complex syndromes, including van der Woude syndrome. A subset of van der Woude cases is caused by dominant-negative mutations in the epithelial transcription factor Grainyhead like-3 (GRHL3), and Grhl3mice have soft-tissue syndactyly. Although impaired interdigital cell death of mesenchymal cells causes syndactyly in multiple genetic mutants, Grhl3 embryos had normal interdigital cell death, suggesting alternative mechanisms for syndactyly.

Specificity of cobamide remodeling, uptake and utilization in Vibrio cholerae.

Cobamides are a group of compounds including vitamin B that can vary at the lower base position of the nucleotide loop. They are synthesized de novo by only a subset of prokaryotes, but some organisms encode partial biosynthesis pathways for converting one variant to another (remodeling) or completing biosynthesis from an intermediate (corrinoid salvaging). Here, we explore the cobamide specificity in Vibrio cholerae through examination of three natural variants representing major cobamide groups: commercially available cobalamin, and isolated pseudocobalamin and p-cresolylcobamide.

NOT Gate Genetic Circuits to Control Gene Expression in Cyanobacteria.

To downregulate gene expression in cyanobacteria, we constructed NOT gate genetic circuits using orthogonal promoters and their cognate repressors regulated translationally by synthetic riboswitches. Four NOT gates were tested and characterized in five cyanobacterial strains using fluorescent reporter-gene assays. In comparison to alternative systems used to downregulate gene expression in cyanobacteria, these NOT gates performed well, reducing YFP reporter expression by 4 to 50-fold.

An Amoebal Grazer of Cyanobacteria Requires Cobalamin Produced by Heterotrophic Bacteria.

Amoebae are unicellular eukaryotes that consume microbial prey through phagocytosis, playing a role in shaping microbial food webs. Many amoebal species can be cultivated axenically in rich media or monoxenically with a single bacterial prey species. Here, we characterize heterolobosean amoeba LPG3, a recent natural isolate, which is unable to grow on unicellular cyanobacteria, its primary food source, in the absence of a heterotrophic bacterium, a species coisolate.

Symmetry of cardiac function assessment.

Both right and left ventricles are developed from two adjacent segments of the primary heart tube. Though they are different with regard to shape and power, they mirror each other in terms of behavior. This is the first level of symmetry in cardiac function assessment.

Microsporidian genome analysis reveals evolutionary strategies for obligate intracellular growth.

Microsporidia comprise a large phylum of obligate intracellular eukaryotes that are fungal-related parasites responsible for widespread disease, and here we address questions about microsporidia biology and evolution. We sequenced three microsporidian genomes from two species, Nematocida parisii and Nematocida sp1, which are natural pathogens of Caenorhabditis nematodes and provide model systems for studying microsporidian pathogenesis. We performed deep sequencing of transcripts from a time course of N.

Cleavage-resistant fusion proteins of the M(2) muscarinic receptor and Gα(i1). Homotropic and heterotropic effects in the binding of ligands.

Background: G protein-coupled receptors fused to a Gα-subunit are functionally similar to their unfused counterparts. They offer an intriguing view into the nature of the receptor-G protein complex, but their usefulness depends upon the stability of the fusion.

Methods: Fusion proteins of the M(2) muscarinic receptor and the α-subunit of G(i1) were expressed in CHO and Sf9 cells, extracted in digitonin-cholate, and examined for their binding properties and their electrophoretic mobility on western blots.

Demands of immigration among Chinese immigrant nurses.

The purpose of this study was to identify the demands of immigration among Chinese nurses that have immigrated to the USA. The relationship between the demands of immigration and length of stay in the USA was investigated also. A descriptive correlational study design was used.

In vivo actin cross-linking induced by Vibrio cholerae type VI secretion system is associated with intestinal inflammation.

Type VI secretion systems (T6SSs) have recently been recognized as potential virulence determinants of many Gram-negative bacterial pathogens. Although mechanistic studies are lacking, T6SS-dependent phenotypes can be observed in various animal models of infection. Presumably translocation of T6SS effectors into target cells is involved in virulence, but few such effectors have been identified.

Translocation of a Vibrio cholerae type VI secretion effector requires bacterial endocytosis by host cells.

The type VI secretion system (T6SS) is a virulence mechanism common to several Gram-negative pathogens. In Vibrio cholerae, VgrG-1 is required for T6SS-dependent secretion. VgrG-1 is also secreted by T6SS and displays a C-terminal actin crosslinking domain (ACD).

Heterooligomers of the muscarinic receptor and G proteins purified from porcine atria.

Muscarinic receptor extracted from porcine atria in digitonin-cholate copurified with Galpha(o), Galpha(i1-3), and caveolins. The presence of complexes was confirmed by coimmunoprecipitation of the receptor, alpha-subunits, and caveolins in various combinations. Homooligomers of alpha(i2) were detected on Western blots, and heterooligomers of alpha(i2) and alpha(o) were identified by coimmunoprecipitation; thus, a complex may contain at least two alpha-subunits.