The tuf gene coding for elongation factor Tu (EF-Tu) of Bacillus stearothermophilus was cloned and sequenced. This gene maps in the same context as the tufA gene of Escherichia coli str operon. Northern-blot analysis and primer extension experiments revealed that the transcription of the tuf gene is driven from two promoter regions. One of these is responsible for producing a 4.9-kb transcript containing all the genes of B. stearothermophilus str operon and the other, identified adjacent to the stop codon of the fus gene and designated tufp, for producing a 1.3-kb transcript of the tuf gene only. In contrast to the situation in E. coli, the ratio between the transcription products was found to be about 10:1 in favour of the tuf gene transcript. This high transcription activity from the tufp promoter might be accounted for by the presence of an extremely A+T-rich block consisting of 29 nucleotides which immediately precedes the consensus -35 region of the promoter. A very similar tuf gene transcription strategy and the same tufp promoter organization with the identical A/T block were found in Bacillus subtilis. The tuf gene specifies a protein of 395 amino acid residues with a molecular mass of 43,290 Da, including the N-terminal methionine. A computer-generated three-dimensional homology model shows that all the structural elements essential for binding guanine nucleotides and aminoacyl-tRNA are conserved. The presence of serine at position 376 and a low affinity for kirromycin determined by zone-interference gel electrophoresis (Kd approximately 8 microM) and by polyacrylamide gel electrophoresis under non-denaturing conditions are in agreement with the reported resistance of this EF-Tu to the antibiotic. The replacement of the highly conserved Leu211 by Met was identified as a possible cause of pulvomycin resistance.
- MeSH
- aminoglykosidy * MeSH
- antibakteriální látky farmakologie MeSH
- antibiotická rezistence MeSH
- DNA bakterií MeSH
- elongační faktor Tu biosyntéza chemie genetika MeSH
- Geobacillus stearothermophilus účinky léků genetika metabolismus MeSH
- konformace proteinů MeSH
- molekulární modely MeSH
- molekulární sekvence - údaje MeSH
- pyridony farmakologie MeSH
- sekvence aminokyselin MeSH
- sekvence nukleotidů MeSH
- sekvenční seřazení MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- aminoglykosidy * MeSH
- antibakteriální látky MeSH
- DNA bakterií MeSH
- elongační faktor Tu MeSH
- mocimycin MeSH Prohlížeč
- pulvomycin MeSH Prohlížeč
- pyridony MeSH
