Disease relevance of tuf

• One such residue, located at position 287 in Escherichia coli EF-Tu, is adjacent to the 5' end of the aa-tRNA and is acidic in all prokaryotic factors but is basic in EF-Tu(mt) [1].
• A feature that is common to both bacteria and to Thermoanaerobacterium sp. appears to be that the lining and the fibrils crossing the cytoplasm contain a high number of copies of the bacterial elongation factor Tu (EF-Tu) [2].
• Direct demonstration of duplicate tuf genes in enteric bacteria [3].
• Thus, as reported for gram-negative bacteria, the cyanobacterium presumably contains two tuf genes [4].
• Analysis, characterization, and loci of the tuf genes in lactobacillus and bifidobacterium species and their direct application for species identification [5].

High impact information on tuf

• Extracts of the tufB- cells contain tuf transcripts that correspond not only in size to the entire 4.5 kb str operon, but also to the size (approximately 1 kb) of a tuf gene [6].
• Visualization of elongation factor Tu on the Escherichia coli ribosome [7].
• Enacyloxin IIa, an inhibitor of protein biosynthesis that acts on elongation factor Tu and the ribosome [8].
• The steps following GTP hydrolysis--the switch of EF-Tu to the GDP-bound conformation, the release of aminoacyl-tRNA from EF-Tu to the A site, and the dissociation of EF-Tu-GDP from the ribosome--which are altogether suppressed by kirromycin, are not distinguished kinetically [9].
• The mechanisms by which elongation factor Tu (EF-Tu) promotes the binding of aminoacyl-tRNA to the A site of the ribosome and, in particular, how GTP hydrolysis by EF-Tu is triggered on the ribosome, are not understood [9].

Chemical compound and disease context of tuf

• Elongation factor Tu resistant to kirromycin in an Escherichia coli mutant altered in both tuf genes [10].
• Structural details of the guanosine diphosphate binding to a modified form of elongation factor Tu from Escherichia coli, resulting from X-ray crystallographic studies, are reported [11].
• Recent suggestions that elongation factor Tu (EF-Tu) is specific for 2'-O-aminoacyl-tRNA, as compared with the 3'-isomer, prompted us to assay [3H]aminoacyl-tRNAs from Escherichia coli terminating in 2'- or 3'-deoxyadenosine for binding to EF-Tu to determine the possible positional specificity of the factor [12].
• The amino acid sequence of elongation factor Tu of Escherichia coli. The large cyanogen bromide peptides [13].
• In Salmonella typhimurium and Escherichia coli, elongation factor Tu (EF-Tu) is methylated as shown by its incorporation of labeled methyl residues from [methyl-3H]methionine [14].

Biological context of tuf

• During protein biosynthesis, elongation factor Tu (EF-Tu) delivers aminoacyl-tRNA (aa-tRNA) to the A-site of the ribosome [1].
• Mutagenesis of Arg335 in bovine mitochondrial elongation factor Tu and the corresponding residue in the Escherichia coli factor affects interactions with mitochondrial aminoacyl-tRNAs [1].
• Our evidence suggests that this 1 kb tuf transcript is derived by posttranscriptional modification of the primary str operon transcript and that this modification could in part explain the high translational efficiency of tuf mRNA [6].
• Frameshifting mediated by the tuf alleles studied, tufA8 and tufB103, is not general; indeed most frameshift mutations are not suppressed [15].
• Inspection of the translated tuf sequence revealed a number of amino acid substitutions in highly conserved positions [16].

Anatomical context of tuf

• The mutations had no effect on EF-Tu-dependent delivery of aminoacyl-tRNA to the ribosome [17].
• Current research and developmental efforts are aimed at the design of a new class of antibacterial drugs, acting by destabilization of the EF-Tu-containing bacterial cytoskeleton, and of an innovative mode of inducible lysis of recombinant bacteria by controlled destabilization of the EF-Tu-containing cytoskeleton [2].
• The P. rosea tuf gene was expressed as a translational fusion to malE in Escherichia coli, and the resulting EF-Tu with an N-terminal Gly-Met extension was able to promote poly(U)-directed poly(Phe) synthesis in cell-free systems [16].
• Results further suggest that the cytoplasmic protein elongation factor Tu is integrated into VHb inclusion bodies [18].
• Functional and structural studies on a tryptic fragment of eucaryotic elongation factor Tu from rabbit reticulocytes [19].

Associations of tuf with chemical compounds

• The importance of P-loop and domain movements in EF-Tu for guanine nucleotide exchange [17].
• Bacteria carryong only one tuf gene from the resistant mutant are still mocimycin sensitive [20].
• Southern analysis confirmed replacement of the chromosomal tufA or tufB gene by a chloramphenicol resistance marker, demonstrating that both tuf genes are individually dispensable for growth [21].
• The purpose of our study was to examine the expression of a cluster of genes that are required for translation in C. trachomatis serovar F: infA (encoding Initiation Factor 1), tRNA(Thr), tuf (encoding Elongation Factor Tu), and tRNA(Trp) [22].
• Its replacement by Asp does not abolish the ability of EF-Tu to sustain protein synthesis [23].

Physical interactions of tuf

• Both EF-Tu(mt) R335E and E. coli EF-Tu E287R have activities comparable to the corresponding wild-type factors in assays using E. coli Phe-tRNA.(Phe) These data suggest that the residue at position 287 plays an important role in the binding and EF-Tu-mediated delivery of mitochondrial aa-tRNAs to the A-site of the ribosome [1].
• An important feature of the nucleotide exchange is the structural rearrangement of EF-Tu in the EF-Tu.EF-Ts complex caused by insertion of Phe-81 of EF-Ts between His-84 and His-118 of EF-Tu [17].

Enzymatic interactions of tuf

• 70S ribosomes, in contrast to 50S subunits, neither release EF-Tu nor rapidly hydrolyze GTP when added to the 30S-EF-Tu complexes [24].

Other interactions of tuf

• Suppression of rpsL phenotypes by tuf mutations reveals a unique relationship between translation elongation and growth rate [25].
• Nucleotide binding proteins, including ras, elongation factor Tu, adenylate kinase, and the mitochondrial F1-ATPase have a glycine-rich motif known as the P-loop or the Walker A sequence (Walker, J. E., Saraste, M., Runswick, M. J., and Gay, N. J. (1982) EMBO J. 1, 945-951) [26].
• In the present paper, we determine the contribution of the contacts between helix D of EF-Tu at the base side of the nucleotide and the N-terminal domain of EF-Ts to the catalysis [27].
• This points to an inhibition mechanism in which EF-Tu is the dominant target of enacyloxin IIa and in which a ribosome with a sensitive EF-Tu blocks mRNA translation for upstream ribosomes with resistant EF-Tus, a mechanism similar to that of the unrelated antibiotic kirromycin [28].
• We propose that the nutrient-dependent methylation of EF-Tu may be involved in the regulation of growth, possibly as a principal component of an unidentified signal transduction pathway in bacteria [29].

Analytical, diagnostic and therapeutic context of tuf

• Site-directed mutagenesis of this residue (Glu287) in E. coli EF-Tu and complementary mutagenesis of the corresponding Arg335 in EF-Tu(mt) was performed to create E. coli EF-Tu E287R and EF-Tu(mt) R335E respectively [1].
• Northern-blot analysis and primer extension experiments revealed that the transcription of the tuf gene is driven from two promoter regions [30].
• Southern blotting, using cloned Escherichia coli tuf sequences as probes, shows that each MudJ insertion results in the physical breakage of the appropriate tuf gene [31].
• The structure of elongation factor Tu (EF-Tu) from thermophilic bacteria, in its 'active' GTP-bound form, has recently been solved by X-ray crystallography [32].
• The composition of the complex of EF-Tu, GTP, and Phe-tRNA(Phe) was studied by gel chromatography [33].

References