Molecular cloning, sequence analysis and expression of the gene for catalase-peroxidase (cpeA) from the photosynthetic bacterium Rhodobacter capsulatus B10.
The gene encoding catalase-peroxidase was cloned from chromosomal DNA of Rhodobacter capsulatus B10. The nucleotide sequence of a 3.7-kb SacI-HindIII fragment, containing the catalase-peroxidase gene (cpeA) and its flanking regions were determined. A 1728-bp open reading frame, coding for 576 amino acid residues (molecular mass 61516 Da) of the enzyme, was observed. A Shine-Dalgarno sequence was found 5 bp upstream from the translational start site. The deduced amino acid sequence coincides with that of the amino terminus and of four peptides derived from trypsin digestion of the purified catalase-peroxidase of R. capsulatus B10. The amino acid sequence of R. capsulatus catalase-peroxidase shows interesting similarities to the amino acid sequences of the hydroperoxidases of Escherichia coli (42.7%) and Salmonella typhimurium (39.9%), the peroxidase of Bacillus stearothermophilus (32.1%) and the catalase-peroxidase of Mycobacterium intracellulare (42.2%). As shown by a cpeA::lacZ fusion in trans in R. capsulatus, the expression of the catalase-peroxidase gene is regulated by oxygen. The promoter of the cpeA gene was localized within 320 bp upstream of the ATG start codon.
Institut für Biologie, Freiburg, Germany.
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Forkl
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Vandekerckhove
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Drews
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Tadros
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D001426:Bacterial Proteins; D001483:Base Sequence; D002374:Catalase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D003001:Cloning, Molecular; D015870:Gene Expression / Q000235:genetics*; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D010544:Peroxidases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D011401:Promoter Regions, Genetic; D016354:Rhodobacter capsulatus / Q000201:enzymology* / Q000235:genetics; D017421:Sequence Analysis
D000596:Amino Acids; D001426:Bacterial Proteins; D010544:Peroxidases; C081610:catalase-peroxidase, bacteria; D002374:Catalase