The catechol 1,2 dioxygenase system of Acinetobacter radioresistens: Isoenzymes, inductors and gene localisation

E. Pessione, M. G. Giuffrida, R. Mazzoli, P. Caposio, S. Landolfo, A. Conti, C. Giunta, G. Gribaudo

Research output: Contribution to journalArticlepeer-review

10 Scopus citations


Two different isozymes (Iso A and Iso B) of catechol 1,2 dioxygenase (C1,20) were isolated from cultures of A. radioresistens grown in two different media, containing phenol and benzoate respectively. In the phenol medium the bacteria expressed about 90% of Iso A, whereas in the benzoate medium the Iso A/Iso B ratio was 40:60. The two proteins have different molecular masses, isoelectric points and N-terminal sequences that are not consistent with simple post-translational modifications. Furthermore, their behaviour differs at high temperatures (42 °C-47 °C) and at moderately acidic pH (pH 6.0): Iso A proved to be the more stable under conditions of environmental stress. Hybridisation analysis with an A. calcoaceticus catA-derived probe revealed that A. radioresistens C1,20 proteins are encoded by two chromosomally located genes. Bidimensional electrophoresis (2DE) maps of crude extracts of cells grown in different carbon sources (phenol, benzoate and acetate) clearly demonstrated a differential induction pattern for the two proteins. The hypothesis of a double set of genes, one for benzoate catabolism and the other for phenol catabolism, is discussed, and analogies are drawn with other known C1,20s.

Original languageEnglish (US)
Pages (from-to)1253-1261
Number of pages9
JournalBiological Chemistry
Issue number8
StatePublished - Oct 4 2001
Externally publishedYes


  • 2DE
  • Benzoate
  • N-terminal sequence comparison
  • Phenol
  • Southern blot analysis

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Clinical Biochemistry


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