Search results for "Biosynthesis"

Protein synthesis of the sponge Geodia cydonium: characterization of the system.

1974

Abstract The ribosomal population of the sponge Geodia cydonium has been examined. The monosomes have a sedimentation constant of 80 S, the sizes of the subunits are approximately 60 S and 45 S respectively. The polyribosomes contain up to 40 ribosomal units. Cell free protein synthesizing systems (cell homogenate as well as reconstituted system) have been prepared and characterized with respect to Mg2+, KCI and ATP concentrations, temperature, pH and time course of the reaction. In the cell-free system and in the cellular system the protein biosynthesis is inhibited by chloramphenicol. It is not affected by cycloheximide.

Differential Translational Efficiency of the mRNAs Isolated from Derepressed and Glucose Repressed Saccharomyces cerevisiae

1987

Summary: Carbon catabolite derepression induced changes in the pool of yeast mRNAs translatable in a protein-synthesizing reticulocyte system. Competition experiments with globin mRNA showed that the mRNA population obtained from derepressed cells possessed a higher translational efficiency than mRNA from repressed cells. The mRNAs that could account for the high translational efficiency of the derepressed mRNA were not detected in cells growing in glucose-rich medium. Analysis of protein synthesis in the presence of 7-methylguanosine 5′-phosphate indicated that the initiation factors recognizing the 5′-terminal structure of capped messengers interacted with lower affinity with the represse…

Molecular Approaches Fighting Nonsense

2021

Nonsense mutations are the result of single nucleotide substitutions in the DNA that change a sense codon (coding for an amino acid) to a nonsense or premature termination codon (PTC) within the coding region of the mRNA [...]

Expression, purification, crystallization and preliminary X-ray analysis of perakine reductase, a new member of the aldo-keto reductase enzyme superf…

2006

Perakine reductase (PR) is a novel member of the aldo-keto reductase enzyme superfamily from higher plants. PR from the plant Rauvolfia serpentina is involved in the biosynthesis of monoterpenoid indole alkaloids by performing NADPH-dependent reduction of perakine, yielding raucaffrinoline. However, PR can also reduce cinnamic aldehyde and some of its derivatives. After heterologous expression of a triple mutant of PR in Escherichia coli, crystals of the purified and methylated enzyme were obtained by the hanging-drop vapour-diffusion technique at 293 K with 100 mM sodium citrate pH 5.6 and 27% PEG 4000 as precipitant. Crystals belong to space group C222(1) and diffract to 2.0 A, with unit-…

Human Enterovirus Group B Viruses Rely on Vimentin Dynamics for Efficient Processing of Viral Nonstructural Proteins.

2019

A virus needs the host cell in order to replicate and produce new progeny viruses. For this, the virus takes over the host cell and modifies it to become a factory for viral proteins. Irrespective of the specific virus family, these proteins can be divided into structural and nonstructural proteins. Structural proteins are the building blocks for the new progeny virions, whereas the nonstructural proteins orchestrate the takeover of the host cell and its functions. Here, we have shown a mechanism that viruses exploit in order to regulate the host cell. We show that viral protein synthesis induces vimentin cages, which promote production of specific viral proteins that eventually control apo…

The Influence of Acetylcholine and Choline on the Incorporation of Phosphate into Phospholipids of Etiolated Bean Hypocotyl Hooks

1980

Summary Acetylcholine influenced the radiolabelling of phospholipids in vivo in etiolated hypocotyl tissue of dwarf beans in darkness. Under aerobic conditions the specific activity of the phospholipids was decreased and under anaerobic conditions increased. The biosynthesis of phospholipids was strongly increased by the bivalent cations calcium and manganese and decreased by 2,4-dinitrophenol, anaerobiosis, atropine and ascorbic acid. Magnesium stimulated the uptake of the radioactive phosphate but not the specific activity of the phospholipids. The results are discussed in comparison with the «phospholipid-effect» of acetylcholine in animal tissues.

Inorganic phosphate is a trigger factor for Microbispora sp. ATCC-PTA-5024 growth and NAI-107 production

2014

Background NAI-107, produced by the actinomycete Microbispora sp. ATCC-PTA-5024, is a promising lantibiotic active against Gram-positive bacteria and currently in late preclinical-phase. Lantibiotics (lanthionine-containing antibiotics) are ribosomally synthesized and post-translationally modified peptides (RiPPs), encoded by structural genes as precursor peptides. The biosynthesis of biologically active compounds is developmentally controlled and it depends upon a variety of environmental stimuli and conditions. Inorganic phosphate (Pi) usually negatively regulates biologically-active molecule production in Actinomycetes, while it has been reported to have a positive control on lantibiotic…

Pigment patterns in mutants affecting the biosynthesis of pteridines and xanthommatin in Drosophila melanogaster.

1986

Eye-color mutants of Drosophila melanogaster have been analyzed for their pigment content and related metabolites. Xanthommatin and dihydroxanthommatin (pigments causing brown eye color) were measured after selective extraction in acidified butanol. Pteridines (pigments causing red eye color) were quantitated after separation of 28 spots by thin-layer chromatography, most of which are pteridines and a few of which are fluorescent metabolites from the xanthommatin pathway. Pigment patterns have been studied in 45 loci. The pteridine pathway ramifies into two double branches giving rise to isoxanthopterin, “drosopterins,” and biopterin as final products. The regulatory relationship among the …

Characterization of two Streptomyces coelicolor A3(2) small orfs from the major locus of histidine biosynthesis.

2009

Disturbances in cholesterol, bile acid and glucose metabolism in peroxisomal 3-ketoacylCoA thiolase B deficient mice fed diets containing high or low…

2014

SPE IPM UB; International audience; : The peroxisomal 3-ketoacyl-CoA thiolase B (ThB) catalyzes the thiolytic cleavage of straight chain 3-ketoacyl-CoAs. Up to now, the ability of ThB to interfere with lipid metabolism was studied in mice fed a routinely laboratory chow enriched or not with the synthetic agonist Wy14,643, a pharmacological activator of the nuclear hormone receptor PPARα. The aim of the present study was therefore to determine whether ThB could play a role in obesity and lipid metabolism when mice are chronically fed a synthetic High Fat Diet (HFD) or a Low Fat Diet (LFD) as a control diet. To investigate this possibility, wild-type (WT) mice and mice deficient for Thb (Thb(…