Search results for "synthesis"

Analysis of expression of an alternative La (SS-B) cDNA and localization of the encoded N- and C-terminal peptides

1997

AbstractA deletion of an (A)-residue was detected in a cDNA encoding for the nuclear autoantigen La/SS-B. The cDNA was recently isolated from a cDNA library made from peripheral blood lymphocytes of a patient with primary Sjögren's Syndrome. The region, where the deletion occurred, represents a hot spot region in the La gene(s). It leads to a frame shift mutation and a premature stop codon eleven amino acids downstream of the deletion site within one of the protease sensitive regions of the La protein. In spite of the frame shift mutation expression of full length La protein occurred efficiently in E. coli. Full length La protein was also made in SF9 cells infected with recombinant baculovi…

Rat adrenoleukodystrophy-related (ALDR) gene: full-length cDNA sequence and new insight in expression.

2001

X-linked adrenoleukodystrophy (X-ALD) is an inherited demyelinating disorder due to mutations in the ALD gene, which encodes a peroxisomal ABC half-transporter (ALDP). It has been suggested that ALDP assembles with ALDRP (adrenoleukodystrophy-related protein), a close homologous half-transporter, to form a functional heterodimer. For the first time full-length ALDRP cDNA (5.5 kb) was cloned, and 5' and 3' RACE analysis revealed that alternative usage of polyadenylation sites generates the two transcripts of 3.0 and 5.5 kb observed in the rat in Northern blot analysis. Southern blotting and chromosomal mapping demonstrated one ALDR locus in the rat genome. Characterisation of the 3' flanking…

Cloning and expression of a cDNA copy of the viral K28 killer toxin gene in yeast

1995

The killer toxin K28, secreted by certain killer strains of the yeast Saccharomyces cerevisiae is genetically encoded by a 1.9 kb double-stranded RNA, M-dsRNA (M28), that is present within the cell as a cytoplasmically inherited virus-like particle (VLP). For stable maintenance and replication, M28-VLPs depend on a second dsRNA virus (LA), which has been shown to encode the major capsid protein (cap) and a capsid-polymerase fusion protein (cap-pol) that provides the toxin-coding M-satellites with their transcription and replicase functions. K28 toxin-coding M28-VLPs were isolated, purified and used in vitro for the synthesis of the single-stranded M28 transcript, which was shown to be of pl…

Arbutin synthase, a novel member of the NRD1β glycosyltransferase family, is a unique multifunctional enzyme converting various natural products and …

2002

Plant glucosyltransferases (GTs) play a crucial role in natural product biosynthesis and metabolization of xenobiotics. We expressed the arbutin synthase (AS) cDNA from Rauvolfia serpentina cell suspension cultures in Escherichia coli with a 6 x His tag and purified the active enzyme to homogeneity. The recombinant enzyme had a temperature optimum of 50 degrees C and showed two different pH optima (4.5 and 6.8 or 7.5, depending on the buffer). Out of 74 natural and synthetic phenols and two cinnamyl alcohols tested as substrates for the AS, 45 were accepted, covering a broad range of structural features. Converting rates comparable to hydroquinone were not achieved. In contrast to this broa…

Acetyltransfer in natural product biosynthesis--functional cloning and molecular analysis of vinorine synthase.

2004

Vinorine synthase (EC 2.3.1.160) catalyses the acetyl-CoA- or CoA-dependent reversible formation of the alkaloids vinorine (or 11-methoxy-vinorine) and 16-epi-vellosimine (or gardneral). The forward reaction leads to vinorine, which is a direct biosynthetic precursor along the complex pathway to the monoterpenoid indole alkaloid ajmaline, an antiarrhythmic drug from the Indian medicinal plant Rauvolfia serpentina. Based on partial peptide sequences a cDNA clone was isolated and functionally expressed in Escherichia coli. The Km values of the native enzyme for gardneral and acetyl-CoA were determined to be 7.5 and 57 microM. The amino acid sequence of vinorine synthase has highest level of i…

Regulation of the biosynthesis of dalbavancin

2009

The primary structural photoresponse of phytochrome proteins captured by a femtosecond X-ray laser

2019

Phytochrome proteins control the growth, reproduction, and photosynthesis of plants, fungi, and bacteria. Light is detected by a bilin cofactor, but it remains elusive how this leads to activation of the protein through structural changes. We present serial femtosecond X-ray crystallographic data of the chromophore-binding domains of a bacterial phytochrome at delay times of 1 ps and 10 ps after photoexcitation. The data reveal a twist of the D-ring, which leads to partial detachment of the chromophore from the protein. Unexpectedly, the conserved so-called pyrrole water is photodissociated from the chromophore, concomitant with movement of the A-ring and a key signaling aspartate. The chan…

Technology-Supported Guidance Models Stimulating the Development of Critical Thinking in Clinical Practice: Protocol for a Mixed Methods Systematic R…

2020

BackgroundCritical thinking is an essential skill that nursing students need to develop. Technological tools have opened new avenues for technology-supported guidance models, but the challenges and facilitators of such guidance models, as well as how they stimulate the development of critical thinking, remain unclear.ObjectiveWe developed a protocol for a mixed methods systematic review to investigate the use of technology-supported guidance models that stimulate the development of critical thinking in nursing education clinical practice.MethodsA convergent integrated design following the Joanna Briggs Institute Manual for Evidence Synthesis will be employed. A pair of authors will select t…

Small Nitrogenous Compounds

1994

Because of the constant turnover of proteins, protein-bound and free amino acids exist in a dynamic equilibrium. The intracellular pool of free amino acids, which is replenished by the hydrolysis of existing proteins, by uptake from the intercellular space and by de novo synthesis, is available for protein synthesis and for the many other metabolic processes dependent upon amino acids. The concentration of free amino acids is always lower than that of the protein-bound residues, one limiting factor being the strong osmotic effects of such low molecular weight compounds. Thus, there is no specific amino acid store in an organism; it is more the case that enzymes and structural proteins thems…

Microbial microstratification, inorganic carbon photoassimilation and dark carbon fixation at the chemocline of the meromictic Lake Cadagno (Switzerl…

2001

The microstratification of the microbial community at the chemocline of Lake Cadagno and the associated inorganic carbon fixation activity was studied by fine layer sampling. A deep chlorophyll maximum caused by diatoms overlying Cryptomonas was found at the upper edge of the chemocline. A high population density of phototrophic sulphur bacteria, mainly Amoebobacter cf. purpureus, occurred closely below the oxic-anoxic boundary. Despite the small fraction of total lake volume represented by the chemocline, half of the total carbon photoassimilation of the lake occurred within the chemocline with approximately equal contributions by oxygenic and anoxygenic phototrophs. Rates of dark carbon f…