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Results 201 - 250 of 1865
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Ogawa Ai - - 2010
G2A is a G protein-coupled receptor that can be induced by various stressors. G2A is reported to have proton-sensing activity that mediates intracellular inositol phosphate (IP) accumulation with decreasing pH. We previously showed that G2A is also activated by some oxidized free fatty acids such as 9-hydroxyoctadecadienoic acid (9-HODE). In ...
Li Congran - - 2010
A unique D-to-L racemization of arginine by coupled arginine dehydrogenases DauA and DauB encoded by the dauBAR operon has been recently reported as a prerequisite for D-arginine utilization as the sole source of carbon and nitrogen through L-arginine catabolic pathways in P. aeruginosa. In this study, enzymic properties of the ...
Wardenga Rainer - - 2010
Aminoacylase-1 from pig kidney (pAcy1) catalyzes the highly stereoselective acylation of amino acids, a useful conversion for the preparation of optically pure N-acyl-l-amino acids. The kinetic of this thermodynamically controlled conversion is determined by maximal velocities for synthesis (V(mS)) and hydrolysis (V(mH)) of the N-acyl-l-amino acid. To investigate which parameter ...
Deweese Joseph E JE Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146, - - 2009
Human topoisomerase IIalpha utilizes a two-metal-ion mechanism for DNA cleavage. One of the metal ions (M(1)(2+)) is believed to make a critical interaction with the 3'-bridging atom of the scissile phosphate, while the other (M(2)(2+)) is believed to interact with a nonbridging oxygen of the scissile phosphate. Based on structural ...
Chung Jung-Sung - - 2009
NMR spectroscopy has been used to map the interaction domain on Escherichia coli thioredoxin for the thioredoxin- dependent 5'-adenylylsulfate reductase from Pseudomonas aeruginosa (PaAPR). Seventeen thioredoxin amino acids, all clustered around Cys-32 (the more surface-exposed of the two active-site cysteines), have been located at the PaAPR binding site. The center ...
Takahashi Tadanobu - - 2009
To identify a determinant of human H3 hemagglutinin (HA) amino acid residues linked to the recognition of molecular species of sialic acid, we generated six mutant viruses possessing either the wild-type HA gene from A/Memphis/1/71 (H3N2) or a genetically single-mutated HA gene at position 137, 144, 155, 158 or 193 ...
Subashchandrabose Sargurunathan - - 2009
In Actinobacillus pleuropneumoniae, which causes porcine pleuropneumonia, ilvI was identified as an in vivo-induced (ivi) gene and encodes the enzyme acetohydroxyacid synthase (AHAS) required for branched-chain amino acid (BCAA) biosynthesis. ilvI and 7 of 32 additional ivi promoters were upregulated in vitro when grown in chemically defined medium (CDM) lacking ...
Dobritsa Anna A - - 2009
Sporopollenin is the major component of the outer pollen wall (exine). Fatty acid derivatives and phenolics are thought to be its monomeric building blocks, but the precise structure, biosynthetic route, and genetics of sporopollenin are poorly understood. Based on a phenotypic mutant screen in Arabidopsis (Arabidopsis thaliana), we identified a ...
Blau-Wasser Rosemarie - - 2009
The Dictyostelium centrosome is a nucleus associated body consisting of a box-shaped core surrounded by the corona, an amorphous matrix functionally equivalent to the pericentriolar material of animal centrosomes which is responsible for the nucleation and anchoring of microtubules. Here we describe CP250 a component of the corona, an acidic ...
Garbarino Jeanne - - 2009
Deletion of the acyltransferases responsible for triglyceride and steryl ester synthesis in Saccharomyces cerevisiae serves as a genetic model of diseases where lipid overload is a component. The yeast mutants lack detectable neutral lipids and cytoplasmic lipid droplets and are strikingly sensitive to unsaturated fatty acids. Expression of human diacylglycerol ...
Hermes Fatemah A M - - 2009
The LipB octanoyltransferase catalyzes the first step of lipoic acid synthesis in Escherichia coli, transfer of the octanoyl moiety from octanoyl-acyl carrier protein to the lipoyl domains of the E2 subunits of the 2-oxoacid dehydrogenases of aerobic metabolism. Strains containing null mutations in lipB are auxotrophic for either lipoic acid ...
Gurvitz Aner - - 2009
Mycobacterium tuberculosis represents a severe threat to human health worldwide. Therefore, it is important to expand our knowledge of vital mycobacterial processes, such as that effected by fatty acid synthase type 2 (FASII), as well as to uncover novel ones. Mycobacterial FASII undertakes mycolic acid biosynthesis, which relies on a ...
Briones-Jurado Claudia - - 2009
The effect of isomorphic substitution on Brønsted acid sites, generated during acid treatment of montmorillonite, was studied using the density functional theory (DFT) and the cluster model method. Cluster models describing acid montmorillonite were constructed and used as a matrix for the protonation of several test molecules under different types ...
Tschumi Andreas - - 2009
Lipoproteins of Gram-negative and Gram-positive bacteria carry a thioether-bound diacylglycerol but differ by a fatty acid amide bound to the alpha-amino group of the universally conserved cysteine. In Escherichia coli the N-terminal acylation is catalyzed by the N-acyltransferase Lnt. Using E. coli Lnt as a query in a BLASTp search, ...
Zakrzewska Malgorzata - - 2009
After binding to its receptor on the surface of mammalian cells and subsequent endocytosis, FGF1 is translocated across the membrane into the cytosol. The growth factor is then further transported into the nucleus. In order to characterize more closely the translocation mechanism utilized by FGF1, we introduced additional amino acids ...
Beauchamp Erwan - - 2009
This study was designed to analyze the effect of myristic acid on ceramide synthesis and its related lipoapoptosis pathway. It was previously observed that myristic acid binds dihydroceramide Delta4-desaturase 1 (DES1) through N-myristoylation and activates this enzyme involved in the final de novo ceramide biosynthesis step. In the present study, ...
Seo Kwang Young KY Biology Department, Boston University, Boston, MA 02215, - - 2009
Y-family DNA polymerases (DNAPs) are often required in cells to synthesize past DNA-containing lesions, such as [+ta]-B[a]P-N(2)-dG, which is the major adduct of the potent mutagen/carcinogen benzo[a]pyrene. The current model for the non-mutagenic pathway in Escherichia coli involves DNAP IV inserting deoxycytidine triphosphate opposite [+ta]-B[a]P-N(2)-dG and DNAP V doing the ...
Schiff Miriam - - 2009
The modification of the neural cell adhesion molecule (NCAM) with polysialic acid plays a pivotal role in the developing nervous system. Here we studied the expression and function of polysialic acid during development of the mesencephalic dopaminergic system of mice. Using immunohistochemistry, polysialic acid was detected on nestin-positive radial glia ...
Mikosch Melanie - - 2009
For a number of ion channels, including the potassium (K(+)) inward rectifying channel from Arabidopsis thaliana (KAT1), diacidic endoplasmic reticulum (ER) export motifs have been identified. These motifs consist of two acidic amino acids (aspartate (D) and/or glutamate (E)) separated by any amino acid. To specify the role of single ...
Bacha Nafees - - 2009
Aspergillus westerdijkiae is the main producer of several biologically active polyketide metabolites including isoasperlactone and asperlactone. A 5298bp polyketide synthase gene "aomsas" has been cloned in Aspergillus westerdijkiae by using gene walking approach and RACE-PCR. The predicted amino acid sequence of aomsas shows an identity of 40-56% with different methylsalicylic ...
Whitehouse Christopher J C - - 2009
The power of proline: Bold amino acid substitutions in sensitive protein regions are frequently unproductive, while more subtle mutations can be sufficient to bring about dramatic changes. But introducing proline at the residue next to the sulfur ligand in P450(BM3) (CYP102A1) has the unexpected and desirable effect of enhancing the ...
Kiziak Christoph - - 2009
The nitrilase from Pseudomonas fluorescens EBC191 converted (R,S)-mandelonitrile with a low enantioselectivity to (R)-mandelic acid and (S)-mandeloamide in a ratio of about 4:1. In contrast, the same substrate was hydrolyzed by the homologous nitrilase from Alcaligenes faecalis ATCC 8750 almost exclusively to (R)-mandelic acid. A chimeric enzyme between both nitrilases ...
Sanchez-Torres Viviana - - 2009
Escherichia coli produces H(2) from formate via the formate hydrogenlyase (FHL) complex during mixed acid fermentation; the FHL complex consists of formate dehydrogenase H (encoded by fdhF) for forming 2H(+), 2e(-), and CO(2) from formate and hydrogenase 3 (encoded by hycGE) for synthesizing H(2) from 2H(+) and 2e(-). FHL protein ...
Jiang Chang-Jie - - 2009
Fatty acids and their derivatives play important signaling roles in plant defense responses. It has been shown that suppressing a gene for stearoyl acyl carrier protein fatty-acid desaturase (SACPD) enhances the resistance of Arabidopsis (SSI2) and soybean to multiple pathogens. In this study, we present functional analyses of a rice ...
Fan Jun - - 2009
We isolated an activation-tagged Arabidopsis (Arabidopsis thaliana) line, constitutive disease susceptibility2-1D (cds2-1D), that showed enhanced bacterial growth when challenged with various Pseudomonas syringae strains. Systemic acquired resistance and systemic PATHOGENESIS-RELATED GENE1 induction were also compromised in cds2-1D. The T-DNA insertion adjacent to NINE-CIS-EPOXYCAROTENOID DIOXYGENASE5 (NCED5), one of six genes encoding ...
Strader Lucia C - - 2009
Plants have developed numerous mechanisms to store hormones in inactive but readily available states, enabling rapid responses to environmental changes. The phytohormone auxin has a number of storage precursors, including indole-3-butyric acid (IBA), which is apparently shortened to active indole-3-acetic acid (IAA) in peroxisomes by a process similar to fatty ...
Yang Zhenle - - 2009
During leaf senescence, macromolecule breakdown occurs and nutrients are translocated to support growth of new vegetative tissues, seeds, or other storage organs. In this study, we determined the fatty acid levels and profiles in Arabidopsis (Arabidopsis thaliana), Brachypodium distachyon, and switchgrass (Panicum virgatum) leaves during natural senescence. In young leaves, ...
Puttick Debbie - - 2009
A cDNA encoding the Arabidopsis extraplastidic linoleate desaturase (FAD3) was overexpressed in the seeds of wild-type Arabidopsis and in a mutant line that accumulates high levels of oleic acid. In the transformed wild-type plants, linolenic acid (18:3Delta9,12,15) increased from 19% to nearly 40% of total seed fatty acids, with a ...
Persky Nicole S NS Department of Biology and Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, MA, - - 2009
The stringent response is important for bacterial survival under stressful conditions, such as amino acid starvation, and is characterized by the accumulation of ppGpp and pppGpp. ObgE (CgtA, YhbZ) is an essential conserved GTPase in Escherichia coli and several observations have implicated the protein in the control of the stringent ...
Pereira Erica Mendes - - 2009
The objective of the present work was to evaluate the relevance of the 2-methylcitric acid cycle (2MCC) to the catabolism of propionate in Burkholderia sacchari. Two B. sacchari mutants unable to grow on propionate were obtained: one disrupted in acnM, and the other in acnM and prpC deleted. An operative ...
Jeong Hee Gon - - 2009
N-acetylneuraminic acid (Neu5Ac, sialic acid) could provide a good substrate for enteropathogenic bacteria in the intestine, when the bacteria invade and colonize in human gut. In order to analyze the role of Neu5Ac catabolism in Vibrio vulnificus pathogenesis, a mutant with disruption of the nanA gene encoding Neu5Ac lyase was ...
Gigolashvili Tamara - - 2009
Aliphatic glucosinolate biosynthesis is highly compartmentalized, requiring import of 2-keto acids or amino acids into chloroplasts for side chain elongation and export of the resulting compounds into the cytosol for conversion into glucosinolate. Aliphatic glucosinolate biosynthesis in Arabidopsis thaliana is regulated by three R2R3-MYB transcription factors, the major player being ...
Liu Feng - - 2009
Catch a tiger by the tail: We have demonstrated that by feeding nonmotile mutant C. jejuni bacteria with a neutral azide-labelled pseudaminic acid precursor we can restore their ability to generate functional flagella. The presence of azido-pseudaminic acid on the surface of the flagella provides a bio-orthogonal chemical handle that ...
Vanderlinde Elizabeth M EM Department of Biology, University of Regina, 3737 Wascana Parkway, Regina, SK S4S 0A2, - - 2009
The lipopolysaccharide (LPS) of the Gram-negative legume symbiont Rhizobium leguminosarum biovar viciae 3,841 contains several unique modifications, including the addition of a 27-hydroxyoctacosanoic acid (27OHC28 : 0), also termed the very long chain fatty acid (VLCFA), attached at the 2' position of lipid A. A transposon mutant that lacks expression ...
Staswick Paul E - - 2009
Most conjugates of plant hormones are inactive, and some function to reduce the active hormone pool. This study characterized the activity of the tryptophan (Trp) conjugate of jasmonic acid (JA-Trp) in Arabidopsis (Arabidopsis thaliana). Unexpectedly, JA-Trp caused agravitropic root growth in seedlings, unlike JA or nine other JA-amino acid conjugates. ...
Yuan Feng-Jie - - 2009
Reduction of phytic acid in soybean seeds has the potential to improve the nutritional value of soybean meal and lessen phosphorus pollution in large scale animal farming. The objective of this study was to assess the effect of two new low phytic acid (LPA) mutations on seed quality and nutritional ...
Beaudoin Frédéric - - 2009
In plants, very-long-chain fatty acids (VLCFAs; >18 carbon) are precursors of sphingolipids, triacylglycerols, cuticular waxes, and suberin. VLCFAs are synthesized by a multiprotein membrane-bound fatty acid elongation system that catalyzes four successive enzymatic reactions: condensation, reduction, dehydration, and a second reduction. A bioinformatics survey of the Arabidopsis (Arabidopsis thaliana) genome ...
Pouget Emmanuel - - 2009
The Lewis acid B(C(6) F(5) )(3) in combination with hydrosilanes exhibits remarkable activity in the oligomerization of sulfone- and phosphonate-based monomers. This process opens new routes to high-tech silicone-based materials, i.e., thermoplastic elastomers and heat-resistant polysiloxanes.
Sakuradani Eiji - - 2009
A filamentous fungus, Mortierella alpina 1S-4, was obtained, through extensive screening, as an potential producer of triacylglycerol containing C20 polyunsaturated fatty acids (PUFAs) such as arachidonic acid. With this discovery as a starting point, we conducted employing methods from metabolic engineering and molecular biology for controlling cultures and breeding mutant ...
Wang Liyun - - 2009
We recently identified a microbial conversion of L-ascorbic acid (AsA) to L-erythroascorbic acid (eAsA), a five-carbon analog of AsA. In this paper, we show that ubiquitin plays a crucial role in this process. Based on an assay that determined AsA decomposition, we purified proteins that had N-terminal amino acid sequences ...
Ntamack André G AG Department of Chemistry, City College and Graduate School of the City University of New York, New York, NY 10031, - - 2009
The beta-oxidation of oleic acid in Saccharomyces cerevisiae (S. cerevisiae) was studied by comparing the growth of wild-type cells on oleic acid or palmitic acid with the growth of mutants that either had a deletion in the YOR180c (DCI1) gene reported to encode delta3,5,delta2,4-dienoyl-CoA isomerase (dienoyl-CoA isomerase) or in the ...
Mäkelä Miia R - - 2009
Oxalate decarboxylase (ODC) catalyses the conversion of oxalic acid to formic acid and CO(2) in bacteria and fungi. In wood-decaying fungi the enzyme has been linked to the regulation of intra- and extracellular quantities of oxalic acid, which is one of the key components in biological decomposition of wood. ODC ...
de Werra Patrice - - 2009
The rhizobacterium Pseudomonas fluorescens CHA0 promotes the growth of various crop plants and protects them against root diseases caused by pathogenic fungi. The main mechanism of disease suppression by this strain is the production of the antifungal compounds 2,4-diacetylphloroglucinol (DAPG) and pyoluteorin (PLT). Direct plant growth promotion can be achieved ...
Piyankarage Sujeewa C - - 2010
This study investigated the effect of different sampling environments on hemolymph amino acid content of individual Drosophila melanogaster larvae. Hemolymph was collected from individual third instar larvae under cold-anesthetized, awake, and stress conditions. Qualitative and quantitative hemolymph amino acid analyses were performed via capillary electrophoresis with laser-induced fluorescence detection. The ...
Tan Xue-Juan - - 2009
A homologue of Sinorhizobium meliloti bacA was isolated from Mesorhizobium huakuii 7653R, which is capable of fixing atmospheric nitrogen in symbiotic association with leguminous Astragalus sinicus (Chinese milk vetch). Inactivation of the bacA gene abolished the ability of M. huakuii 7653R to establish a successful symbiosis with its host plant. ...
Otsuki Hitoshi - - 2009
The major virulence determinant of the rodent malaria parasite, Plasmodium yoelii, has remained unresolved since the discovery of the lethal line in the 1970s. Because virulence in this parasite correlates with the ability to invade different types of erythrocytes, we evaluated the potential role of the parasite erythrocyte binding ligand, ...
Harris Muriel J - - 2009
Almost 30 years after the initial study by Richard W. Smithells and coworkers, it is still unknown how maternal periconceptional folic acid supplementation prevents human neural tube defects (NTDs). In this article, questions about human NTD prevention are considered in relation to three groups of mouse models: NTD mutants that ...
Hughes Austin L AL Department of Biological Sciences, Coker Life Sciences Building, 715 Sumter St., University of South Carolina, Columbia SC 29208, USA. - - 2009
We examined the pattern of nucleotide substitution in 4933 conserved single-copy orthologous protein-coding genes of human, rhesus, mouse, and rat. Consistent with previous studies, the median ratio of the number of nonsynonymous substitutions per nonsynonymous site (d(N)) to the number of synonymous substitutions per synonymous site (d(S)) was significantly higher ...
Garscha Ulrike - - 2009
Linoleate (10R)-dioxygenase (10R-DOX) of Aspergillus fumigatus was cloned and expressed in insect cells. Recombinant 10R-DOX oxidized 18:2n-6 to (10R)-hydroperoxy-8(E),12(Z)-octadecadienoic acid (10R-HPODE; approximately 90%), (8R)-hydroperoxylinoleic acid (8R-HPODE; approximately 10%), and small amounts of 12S(13R)-epoxy-(10R)-hydroxy-(8E)-octadecenoic acid. We investigated the oxygenation of 18:2n-6 at C-10 and C-8 by site-directed mutagenesis of 10R-DOX and ...
Li Zejun - - 2009
The nucleoprotein (NP), which has multiple functions during the virus life cycle, possesses regions that are highly conserved among influenza A, B, and C viruses. To better understand the roles of highly conserved NP amino acids in viral replication, we conducted a comprehensive mutational analysis. Using reverse genetics, we attempted ...
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