Primary structure and characterization of the vanadium chloroperoxidase from the fungus Curvularia inaequalis
| Autor: | Bert Simons, Henk L. Dekker, Albrecht Messerschmidt, Anton O. Muijsers, E.G.M. Vollenbroek, Philip Barnett, Ron Wever |
|---|---|
| Přispěvatelé: | Other departments |
| Rok vydání: | 1995 |
| Předmět: |
DNA
Complementary Sequence analysis Genes Fungal Molecular Sequence Data Gene Expression Biology Biochemistry Fungal Proteins chemistry.chemical_compound Complementary DNA Amino Acid Sequence Disulfides RNA Messenger Cloning Molecular Peptide sequence Glycoproteins chemistry.chemical_classification Methionine Base Sequence Sequence Homology Amino Acid Protein primary structure Fungi Vanadium Amino acid genomic DNA chemistry Chloride Peroxidase Peptides Sequence Alignment Cysteine |
| Zdroj: | European Journal of Biochemistry / FEBS, 229(2), 566-574. Wiley-Blackwell |
| ISSN: | 0014-2956 |
| Popis: | Using reverse transcription of messenger RNA followed by amplification using the polymerase chain reaction, three overlapping cDNA fragments encompassing the encoding sequence of the vanadium chloroperoxidase from the fungus Curvularia inaequalis were isolated and sequenced. The sequence was confirmed by DNA sequence analysis of genomic DNA. The deduced amino acid sequence predicts a protein of 609 residues with a mass of 67488 Da. Competitive reverse-transcription polymerase chain reaction analysis indicates that vanadium chloroperoxidase expression takes place in the secondary-growth phase initiated by nutrient depletion. Southern-blot analysis of genomic DNA indicates that there is only a single gene encoding the vanadium chloroperoxidase and that no isoenzymes are present. The N-terminal amino acid residue was blocked and could not be determined by amino acid sequencing, although evidence is presented showing that the N-terminal region starts very close to the first encoded methionine residue. Although the vanadium chloroperoxidase is secreted, it was not possible to assign a leader peptide. The protein contains two putative N-glycosylation sites but experiments indicate that the protein is non-glycosylated. Two cysteine residues are present in the protein both as free thiols: no disulphide bridging was found. Metal analysis revealed that iron, copper, and calcium do not constitute part of the protein. Zinc was found at a ratio of 0.3 +/- 0.04 mol/mol protein. Boiling and subsequent SDS/PAGE of the protein sample showed a typical degradation pattern of the enzyme. Amino acid sequence analysis of the resulting peptides showed that the cleavage took place at Asp-Pro bonds of which six are located throughout the protein. No sequence similarity with other known peroxidases was found except for one small region, sharing limited similarity with bacterial haloperoxidases and other alpha/beta-hydrolase-fold enzymes. In the case of the bacterial bromoperoxidases from this group, a methionine located in this region was suggested to have a role in catalysis. Methionine, however, was not involved in the catalysis of the vanadium chloroperoxidase. |
| Databáze: | OpenAIRE |
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