The complete amino acid sequence of 3-dehydroquinate synthase of Escherichia coli K 12

AbstractThe complete amino acid sequence of the Escherichia coli 3-dehydroquinate synthase has been determined by a combined nucleotide and direct amino acid sequencing strategy. E. coli 3-dehydroquinate synthase is 362 amino acids long and has a calculated Mr of 38 880. Analysis of the aroB nucleotide sequence and its 5'- and 3'-flanking regions has identified the aroB promoter elements and a possible 3'-terminator site

Crystallization and preliminary X-ray analysis of shikimate dehydrogenase fromEscherichia coli

Shikimate dehydrogenase from Escherichia coli has been crystallized by the vapour-diffusion method using ammonium sulfate as a precipitant. Mass spectrometry confirmed the purity of the enzyme and dynamic light scattering was used to find the appropriate additives to yield a monodisperse enzyme solution. The crystals are monoclinic, space group C2, with unit-cell parameters a = 110.0, b = 139.8, c = 102.6 Å, [beta] = 122.2° (at 100 K). Native crystals diffract to 2.3 Å in-house on a rotating-anode X-ray source. The asymmetric unit is likely to contain four molecules, related by 222 symmetry, corresponding to a packing density of 2.86 Å3 Da-1

The two types of 3-dehydroquinase have distinct structures but catalyze the same overall reaction

The structures of enzymes catalyzing the reactions in central metabolic pathways are generally well conserved as are their catalytic mechanisms. The two types of 3-dehydroquinate dehydratase (DHQase) are therefore most unusual since they are unrelated at the sequence level and they utilize completely different mechanisms to catalyze the same overall reaction. The type I enzymes catalyze a cis-dehydration of 3-dehydroquinate via a covalent imine intermediate, while the type II enzymes catalyze a trans-dehydration via an enolate intermediate. Here we report the three-dimensional structures of a representative member of each type of biosynthetic DHQase.Both enzymes function as part of the shikimate pathway, which is essential in microorganisms and plants for the biosynthesis of aromatic compounds including folate, ubiquinone and the aromatic amino acids. An explanation for the presence of two different enzymes catalyzing the same reaction is presented. The absence of the shikimate pathway in animals makes it an attractive target for antimicrobial agents. The availability of these two structures opens the way for the design of highly specific enzyme inhibitors with potential importance as selective therapeutic agents

The Australasian Resuscitation In Sepsis Evaluation: FLUid or vasopressors In Emergency Department Sepsis, a multicentre observational study (ARISE FLUIDS observational study): Rationale, methods and analysis plan

There is uncertainty about the optimal i.v. fluid volume and timing of vasopressor commencement in the resuscitation of patients with sepsis and hypotension. We aim to study current resuscitation practices in EDs in Australia and New Zealand (the Australasian Resuscitation In Sepsis Evaluation: FLUid or vasopressors In Emergency Department Sepsis [ARISE FLUIDS] observational study).ARISE FLUIDS is a prospective, multicentre observational study in 71 hospitals in Australia and New Zealand. It will include adult patients presenting to the ED during a 30 day period with suspected sepsis and hypotension (systolic blood pressur

Cancer health disparities in racial/ethnic minorities in the United States

There are well-established disparities in cancer incidence and outcomes by race/ethnicity that result from the interplay between structural, socioeconomic, socio-environmental, behavioural and biological factors. However, large research studies designed to investigate factors contributing to cancer aetiology and progression have mainly focused on populations of European origin. The limitations in clinicopathological and genetic data, as well as the reduced availability of biospecimens from diverse populations, contribute to the knowledge gap and have the potential to widen cancer health disparities. In this review, we summarise reported disparities and associated factors in the United States of America (USA) for the most common cancers (breast, prostate, lung and colon), and for a subset of other cancers that highlight the complexity of disparities (gastric, liver, pancreas and leukaemia). We focus on populations commonly identified and referred to as racial/ethnic minorities in the USA—African Americans/Blacks, American Indians and Alaska Natives, Asians, Native Hawaiians/other Pacific Islanders and Hispanics/Latinos. We conclude that even though substantial progress has been made in understanding the factors underlying cancer health disparities, marked inequities persist. Additional efforts are needed to include participants from diverse populations in the research of cancer aetiology, biology and treatment. Furthermore, to eliminate cancer health disparities, it will be necessary to facilitate access to, and utilisation of, health services to all individuals, and to address structural inequities, including racism, that disproportionally affect racial/ethnic minorities in the USA.Fil: Zavala, Valentina A.. University of California; Estados UnidosFil: Bracci, Paige M.. University of California; Estados UnidosFil: Carethers, John M.. University of Michigan; Estados UnidosFil: Carvajal Carmona, Luis. University of California at Davis; Estados UnidosFil: Coggins, Nicole B.. University of California at Davis; Estados UnidosFil: Cruz Correa, Marcia R.. Universidad de Puerto Rico; Puerto RicoFil: Davis, Melissa. No especifíca;Fil: de Smith, Adam J.. University of California; Estados UnidosFil: Dutil, Julie. Ponce Research Institute; Puerto RicoFil: Figueiredo, Jane C.. Cedars Sinai Medical Center; Estados UnidosFil: Fox, Rena. University of California; Estados UnidosFil: Graves, Kristi D.. University Of Georgetown; Estados UnidosFil: Gomez, Scarlett Lin. University of California; Estados UnidosFil: Llera, Andrea Sabina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Neuhausen, Susan L.. No especifíca;Fil: Newman, Lisa. No especifíca;Fil: Nguyen, Tung. University of California; Estados UnidosFil: Palmer, Julie R.. National Institutes of Health; Estados UnidosFil: Palmer, Nynikka R.. University of California; Estados UnidosFil: Pérez Stable, Eliseo J.. National Institutes of Health; Estados UnidosFil: Piawah, Sorbarikor. University of California; Estados UnidosFil: Rodriquez, Erik J.. National Institutes of Health; Estados UnidosFil: Sanabria Salas, María Carolina. Instituto Nacional de Cancerología; ColombiaFil: Schmit, Stephanie L.. University of Southern California; Estados UnidosFil: Serrano Gomez, Silvia J.. Instituto Nacional de Cancerología; ColombiaFil: Stern, Mariana Carla. University of Southern California; Estados UnidosFil: Weitzel, Jeffrey. No especifíca;Fil: Yang, Jun J.. St. Jude Children’s Research Hospital; Estados UnidosFil: Zabaleta, Jovanny. No especifíca;Fil: Ziv, Elad. University of California; Estados UnidosFil: Fejerman, Laura. University of California; Estados Unido

Probabilistic Interaction Network of Evidence Algorithm and its Application to Complete Labeling of Peak Lists from Protein NMR Spectroscopy

The process of assigning a finite set of tags or labels to a collection of observations, subject to side conditions, is notable for its computational complexity. This labeling paradigm is of theoretical and practical relevance to a wide range of biological applications, including the analysis of data from DNA microarrays, metabolomics experiments, and biomolecular nuclear magnetic resonance (NMR) spectroscopy. We present a novel algorithm, called Probabilistic Interaction Network of Evidence (PINE), that achieves robust, unsupervised probabilistic labeling of data. The computational core of PINE uses estimates of evidence derived from empirical distributions of previously observed data, along with consistency measures, to drive a fictitious system M with Hamiltonian H to a quasi-stationary state that produces probabilistic label assignments for relevant subsets of the data. We demonstrate the successful application of PINE to a key task in protein NMR spectroscopy: that of converting peak lists extracted from various NMR experiments into assignments associated with probabilities for their correctness. This application, called PINE-NMR, is available from a freely accessible computer server (http://pine.nmrfam.wisc.edu). The PINE-NMR server accepts as input the sequence of the protein plus user-specified combinations of data corresponding to an extensive list of NMR experiments; it provides as output a probabilistic assignment of NMR signals (chemical shifts) to sequence-specific backbone and aliphatic side chain atoms plus a probabilistic determination of the protein secondary structure. PINE-NMR can accommodate prior information about assignments or stable isotope labeling schemes. As part of the analysis, PINE-NMR identifies, verifies, and rectifies problems related to chemical shift referencing or erroneous input data. PINE-NMR achieves robust and consistent results that have been shown to be effective in subsequent steps of NMR structure determination

The Australasian Resuscitation In Sepsis Evaluation : fluids or vasopressors in emergency department sepsis (ARISE FLUIDS), a multi-centre observational study describing current practice in Australia and New Zealand

Objectives: To describe haemodynamic resuscitation practices in ED patients with suspected sepsis and hypotension. Methods: This was a prospective, multicentre, observational study conducted in 70 hospitals in Australia and New Zealand between September 2018 and January 2019. Consecutive adults presenting to the ED during a 30-day period at each site, with suspected sepsis and hypotension (systolic blood pressure <100 mmHg) despite at least 1000 mL fluid resuscitation, were eligible. Data included baseline demographics, clinical and laboratory variables and intravenous fluid volume administered, vasopressor administration at baseline and 6- and 24-h post-enrolment, time to antimicrobial administration, intensive care admission, organ support and in-hospital mortality. Results: A total of 4477 patients were screened and 591 were included with a mean (standard deviation) age of 62 (19) years, Acute Physiology and Chronic Health Evaluation II score 15.2 (6.6) and a median (interquartile range) systolic blood pressure of 94 mmHg (87–100). Median time to first intravenous antimicrobials was 77 min (42–148). A vasopressor infusion was commenced within 24 h in 177 (30.2%) patients, with noradrenaline the most frequently used (n = 138, 78%). A median of 2000 mL (1500–3000) of intravenous fluids was administered prior to commencing vasopressors. The total volume of fluid administered from pre-enrolment to 24 h was 4200 mL (3000–5661), with a range from 1000 to 12 200 mL. Two hundred and eighteen patients (37.1%) were admitted to an intensive care unit. Overall in-hospital mortality was 6.2% (95% confidence interval 4.4–8.5%). Conclusion: Current resuscitation practice in patients with sepsis and hypotension varies widely and occupies the spectrum between a restricted volume/earlier vasopressor and liberal fluid/later vasopressor strategy