Publications by authors named "Jens Nyborg"

Background: While all codons that specify amino acids are universally recognized by tRNA molecules, codons signaling termination of translation are recognized by proteins known as class-I release factors (RF). In most eukaryotes and archaea a single RF accomplishes termination at all three stop codons. In most bacteria, there are two RFs with overlapping specificity, RF1 recognizes UA(A/G) and RF2 recognizes U(A/G)A.

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The third component of complement (C3) is a 190 kDa glycoprotein essential for eliciting the complement response. The protein consists of two polypeptide chains (alpha and beta) held together with a single disulfide bridge. The beta-chain is composed of six MG domains, one of which is shared with the alpha-chain.

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Pulvomycin inhibits protein synthesis by preventing the formation of the ternary complex between elongation factor Tu (EF-Tu) x GTP and aa-tRNA. In this work, the crystal structure of Thermus thermophilus EF-Tu x pulvomycin in complex with the GTP analogue guanylyl imino diphosphate (GDPNP) at 1.4 A resolution reveals an antibiotic binding site extending from the domain 1-3 interface to domain 2, overlapping the domain 1-2-3 junction.

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Elongation factor (EF-) Tu.GTP is the carrier of aminoacyl-tRNA to the programmed ribosome. Enacyloxin IIa inhibits bacterial protein synthesis by hindering the release of EF-Tu.

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The secondary structures of metazoan mitochondrial (mt) tRNAs(Ser) deviate markedly from the paradigm of the canonical cloverleaf structure; particularly, tRNA(Ser)(GCU) corresponding to the AGY codon (Y=U and C) is highly truncated and intrinsically missing the entire dihydrouridine arm. None of the mt serine isoacceptors possesses the elongated variable arm, which is the universal landmark for recognition by seryl-tRNA synthetase (SerRS). Here, we report the crystal structure of mammalian mt SerRS from Bos taurus in complex with seryl adenylate at an atomic resolution of 1.

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The three-dimensional structure of the bovine mitochondrial elongation factor (EF)-Tu.Ts complex (EF-Tumt.Tsmt) has been determined to 2.

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The mitochondrial seryl-tRNA synthetase (mt SerRS) from Bos taurus was overexpressed in Escherichia coli and crystallized using the sitting-drop vapour-diffusion method. Crystals grew in a very narrow range of conditions using PEG 8000 as precipitant at room temperature. An appropriate concentration of lithium sulfate was critical for crystal nucleation.

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The crystal structure of the N-terminal 219 residues (domain 1) of the conserved eukaryotic translation elongation factor 1Bgamma (eEF1Bgamma), encoded by the TEF3 gene in Saccharomyces cerevisiae, has been determined at 3.0 A resolution by the single wavelength anomalous dispersion technique. The structure is overall very similar to the glutathione S-transferase proteins and contains a pocket with architecture highly homologous to what is observed in glutathione S-transferase enzymes.

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Translation elongation factors are the workhorses of protein synthesis on the ribosome. They assist in elongating the nascent polypeptide chain by one amino acid at a time. The general biochemical outline of the translation elongation cycle is well preserved in all biological kingdoms.

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A procedure for large-scale isolation of plasmid DNA without the use of RNase has been developed to obtain a DNA template for preparative in vitro RNA synthesis catalyzed by phage RNA polymerases. The separation of plasmid DNA from admixtures has been achieved only through selective precipitations of either plasmid DNA or contaminants. No expensive reagents or equipment were required.

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The interaction of a Thermus thermophilus tmRNA transcript with alanyl-tRNA synthetase and elongation factor Tu has been studied. The synthetic tmRNA was found to be stable up to 70 degrees C. The thermal optimum of tmRNA alanylation was determined to be around 50 degrees C.

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Life in hot environments poses certain constraints on the metabolism of thermophilic organisms. Many universal metabolic intermediates are quite labile compounds, and without protection will rapidly decompose at elevated temperatures. Among these are aminoacyl-tRNAs that are necessarily formed upon functioning of the translation apparatus.

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Previous studies have shown that when bovine mitochondrial elongation factor Ts (EF-Ts) is expressed in Escherichia coli, it forms a tightly associated complex with E. coli elongation factor Tu (EF-Tu). In contrast to earlier experiments, purification of free mitochondrial EF-Ts was accomplished under nondenaturing conditions since only about 60% of the expressed EF-Ts copurified with E.

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