Publications by authors named "Alex Tucker"

The asphaltophone is a musical instrument consisting of (1) a specially designed road surface topology, (2) the tire's contact patch, and (3) the vehicle itself. Each of these components in the asphaltophone has an analogy in the phonograph, which is composed of (1) a record, (2) a stylus, and (3) an amplification device. Asphaltophones are an enjoyable and inexpensive method to keep drivers alert and develop tourism.

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In nature, organic acids are a commonly used source of carbon and energy. Many bacteria use AMP-forming acid:CoA ligases to convert organic acids into their corresponding acyl-CoA derivatives, which can then enter metabolism. The soil environment contains a broad diversity of organic acids, so it is not surprising that bacteria such as Streptomyces lividans can activate many of the available organic acids.

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Background: Sacral chordomas are rare, slow growing, locally aggressive tumors. Unfortunately, aggressive surgical resection is often associated with increased neurological morbidity.

Methods: This technical note focuses on the utilization of partial sacrectomy for the resection of complex spinal chordomas.

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Background: Chordomas are uncommon malignant bone tumors that are often minimally symptomatic for several years. By the time they are diagnosed, these lesions are typically large, involve major neural, bony, and vascular structures, and are no longer readily resectable. This leads to a high recurrence rate.

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Gram-negative bacteria secrete proteins using a type III secretion system (T3SS), which functions as a needle-like molecular machine. The many proteins involved in T3SS construction are tightly regulated due to its role in pathogenesis and motility. Here, starting with the 35 kb Salmonella pathogenicity island 1 (SPI-1), we eliminated internal regulation and simplified the genetics by removing or recoding genes, scrambling gene order and replacing all non-coding DNA with synthetic genetic parts.

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Engineering commensal organisms for challenging applications, such as modulating the gut ecosystem, is hampered by the lack of genetic parts. Here, we describe promoters, ribosome-binding sites, and inducible systems for use in the commensal bacterium , a prevalent and stable resident of the human gut. We achieve up to 10,000-fold range in constitutive gene expression and 100-fold regulation of gene expression with inducible promoters and use these parts to record DNA-encoded memory in the genome.

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The adenosine monoposphate-forming acyl-CoA synthetase enzymes catalyze a two-step reaction that involves the initial formation of an acyl adenylate that reacts in a second partial reaction to form a thioester between the acyl substrate and CoA. These enzymes utilize a Domain Alternation catalytic mechanism, whereby a ∼ 110 residue C-terminal domain rotates by 140° to form distinct catalytic conformations for the two partial reactions. The structure of an acetoacetyl-CoA synthetase (AacS) is presented that illustrates a novel aspect of this C-terminal domain.

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Reversible lysine acetylation by protein acetyltransferases is a conserved regulatory mechanism that controls diverse cellular pathways. Gcn5-related N-acetyltransferases (GNATs), named after their founding member, are found in all domains of life. GNATs are known for their role as histone acetyltransferases, but non-histone bacterial protein acetytransferases have been identified.

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Lung disease in people with cystic fibrosis (CF) is initiated by defective host defense that predisposes airways to bacterial infection. Advanced CF is characterized by a deficit in mucociliary transport (MCT), a process that traps and propels bacteria out of the lungs, but whether this deficit occurs first or is secondary to airway remodeling has been unclear. To assess MCT, we tracked movement of radiodense microdisks in airways of newborn piglets with CF.

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Reversible lysine acetylation (RLA) is a widespread regulatory mechanism that modulates the function of proteins involved in diverse cellular processes. A strong case has been made for RLA control exerted by homologues of the Salmonella enterica protein acetyltransferase (SePat) enzyme on the broadly distributed AMP-forming CoA ligase (a.k.

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GCN5-type N-acetyltransferases (GNATs) are enzymes that catalyse the transfer of the acetyl group from acetyl-CoA to a primary amine. GNATs are conserved in all domains of life. Some members of this family of enzymes acetylate the side-chain of specific lysine residues in proteins of diverse function.

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Unlabelled: Coenzyme A (CoA) is essential for cellular chemistry in all forms of life. The pantothenate moiety of CoA is generated from the condensation of pantoate and β-alanine. β-Alanine is formed by decarboxylation of l-aspartate catalyzed by PanD, a pyruvoyl enzyme that is synthesized by the cell as an inactive precursor (pro-PanD).

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Sirtuins are NAD(+)-dependent protein deacylases that are conserved in all domains of life and are involved in diverse cellular processes, including control of gene expression and central metabolism. Eukaryotic sirtuins have N-terminal extensions that have been linked to protein multimerization and cellular localization. Here the first evidence of sirtuin isoforms in bacteria is reported.

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