Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 54 for “"s-adenosylmethionine"”.
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EFFECT OF NICOTINE ON LUNG S-ADENOSYLMETHIONINE AND PNEUMOCYSTIS PNEUMONIA DEVELOPMENT
… causes a ≥ 99% depletion of plasma S-adenosylmethionine (AdoMet) levels in both "Pneumocystis" pneumonia (PcP) animal models and patients. AdoMet is a critical cellular metabolic intermediate, with a pivotal role as methyl donor in a myriad of biochemical processes and necessary for …
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The Role of S-Adenosylmethionine Synthetase in Killing Effects of DFMO in African Trypanosomes
… allowed me to test the effects of decreasing S-Adenosylmethionine Synthetase (AdoMetSyn) levels on eflornithine toxicity. I found that knockdown of AdoMetSyn mRNA led to reduced growth rates and to a reduction in AdoMet and dcAdoMet levels in the cell. The potency of DFMO was increased when …
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Vitamin B12 impacts amyloid-β induced proteotoxicity by regulating the methionine/s-adenosylmethionine cycle
… the dietary shift. Increased methionine/S-adenosylmethionine (SAMe) cycle activity can increase the synthesis of membrane phosphatidylcholine (PtdCho) through SAMe dependent methylation of phosphoethanolamine. Supplementation with either choline or PtdCho delayed Aβ-induced paralysis. …
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A study of the metK gene encoding S-adenosylmethionine synthetase in Escherichia coli K-12
The metK gene of Escherichia coli encodes S-adenosylmethionine synthetase, which catalyzes the reaction between L-methionine and ATP to form S-adenosylmethionine (SAM), the universal methyl group donor in the cell. SAM synthetase is generally assumed to be essential in E. coli , but this has not …
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The Role of S-Adenosylmethionine Decarboxylase on Regulation of Polyamine and Trypanothione Metabolism in Trypanosoma Brucei
… drug targets. We have characterized T. brucei S-adenosylmethionine decarboxylase (AdoMetDC), a key enzyme required for the synthesis of spermidine and trypanothione, and examined the role of AdoMetDC on the regulation of polyamine and trypanothione metabolism. The recombinant T. brucei AdoMetDC …
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Characterization of a mutation demonstrating a link between the lack of S-adenosylmethionine and cell division in Escherichia coli
… of Escherichia coli encodes for the enzyme S-adenosylmethionine (SAM) synthetase, which catalyzes the formation of S-adenosylmethionine. Isolated as a $\gamma$-glutamylmethyl ester-resistant mutant by Greene et al. (1973), a metK84 mutant grows normally on rich media (Greene et al. 1973; Lin …
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Crystallization studies of 5'-deoxyadenosyl radical enzymes
Both adenosylcobalamin- and S-adenosylmethionine-dependent radical enzymes use a 5'-deoxyadenosyl radical intermediate to abstract a hydrogen atom from their substrates. In the case of adenosylcobalamin-dependent enzymes, the 5'-deoxyadenosyl radical is generated by homolytic cleavage of the …
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Characterization of Cyclopropyl Synthases Involved in the Maturation of Ribosomally Synthesized and Posttranslationally Modified Peptides
… enzymes, or maturases. Recently, radical-S-adenosylmethionine (rSAM) enzymes have emerged as an important family of RiPP maturases. rSAM enzymes have been shown to install ether, thioether, and carbon-carbon bonds on the precursor peptide. These modifications usually define the backbone …
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Archaeal Gene Identification
… Another section identifies an archaeal-type S-adenosylmethionine synthetase that is highly diverged from well-studied bacterial and eucaryal homologs. Studies of tRNA modification enzymes from M. jannaschii identify 7 enzymes, which use S-adenosylmethionine to methylate tRNAs in vitro . …
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SAM Homeostasis Is Regulated by CFIm-Mediated Splicing of MAT2A
S-adenosylmethionine (SAM) is the methyl donor for nearly all cellular methylation events. Cells regulate intracellular SAM levels through intron detention of MAT2A, the only SAM synthetase expressed in most cells. The N6-adenosine methyltransferase METTL16 promotes splicing of the MAT2A detained …
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Signal transduction in human cells by metabolites derived from methionine and glucose
… Moreover, we show that SAMTOR is an S-adenosylmethionine binding protein, and that SAM binding disrupts the SAMTOR-GATOR1 interaction. SAM is a derivative of methionine, and we show that methionine starvation promotes SAMTOR action on GATOR1 following a decrease in SAM levels.
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Identification of Quorum Sensing Genes in Hypersaline Microbial Mats
… identified genes involved in the synthesis of S-adenosylmethionine (SAM) transferases. S-adenosylmethionine is the precursor for the production of acyl-homoserine lactones (AHL) or autoinducer-2 (AI-2) depending on the biosynthetic pathway. This suggests that the synthesis of QS signaling …
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Polyamine metabolism in Arabidopsis: Transgenic manipulation and gene expression
… expression patterns of Arabidopsis thaliana S-adenosylmethionine decarboxylase genes (AtSAMDC3, AtSAMDC4 and AtSAMDC5) during its life cycle.</p><p>The major findings are: (i) Orn becomes a limiting substrate for Put biosynthesis in transgenic Arabidopsis expressing mODC gene, (ii) Put …
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Understanding polyamine metabolism through transgenic manipulation in poplar suspension cultures
… enzyme, (ii) decreased expression of S-adenosylmethionine gene and activity of the enzyme, (iii) changes in the cellular contents of almost all amino acids, (iv) a compromise in cell health due to increased oxidative stress, (v) better tolerance towards Aluminum toxicity, (vi) increased …
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Purification, characterization and substrate specificity of a nuclear mRNA (Guanine-7)-Methyltransferase from Ehrlich ascites cells
… catalyzed the methyl group transfer from S-adenosylmethionine to a capped but unmethylated RNA substrate. The purified enzyme had an apparent native molecular weight of 95,000, as determined by gel filtration chromatography. SDS-PAGE showed a predominant protein band of 46,000 daltons …
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Studies on CheA(B): Phosphorylation, methylation and behavioral control during chemotactic signal transduction in Bacillus subtilis
… an acceptor and replaced by methyl groups from S-adenosylmethionine, is regulated by CheB$\sb{\rm B}$, whose activity is controlled by CheA$\sb{\rm B}$.
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Structures and Regulation of the N6-Methyladenosine Methyltransferase METTL16
… is deposited by methyltransferases using S-adenosylmethionine (SAM) as the methyl donor. Determining the specificity and mechanism of action of m6A methyltransfersaes is an essential step in dissecting the role of the m6A modification in RNA metabolism. Two enzymes that are responsible for …
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Characterization of the expression profile of polyamine biosynthetic genes (Spermidine synthase) and polyamine metabolic regulation in arabidopsis
… Plasmodium falciparum ornithine decarboxylase/S-adenosylmethionine decarboxylase) altered spermidine/spermine content much, which indicates a complex and tightly regulated machinery for higher polyamine homeostasis. The turn-over study on all three major polyamines showed a short half-life of 6-8 …
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Studies of thiamine biosynthesis
… shows sequence similarity with the ‘radical S-adenosylmethionine’ (AdoMet) family of proteins, including conserved cysteine ligands to the essential [4Fe-4S] cluster and has been shown to form a complex with ThiG. With the purpose of studying the mechanistic enzymology by which Thz-P is …
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Characterization of mutant N², N²-dimethylguanosine-specific tRNA methyltransferases from Saccharomyces cerevisiae
… (m$\sbsp{2}{2}$Gtase) is an enzyme which uses S-adenosylmethionine as a substrate to catalyze the transfer of two methyl groups to the 2-amino group of guanosine at position 26 in tRNA. Neither the tertiary structure nor the location of the active sites are known for m$\sbsp{2}{2}$Gtase. In an …
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