Purification, biochemical properties and substrate specificity of a catechol 1,2‐dioxygenase from a phenol degrading Acinetobacter radioresistens

FEBS Letters

Pessione, Enrica²  Briganti, Fabrizio¹  Giunta, Carlo²  Scozzafava, Andrea¹ 

[1] Laboratorio di Chimica Inorganica e Bioinorganica, Dipartimento di Chimica, Università degli Studi di Firenze, Via Gino Capponi 7, 50121 Florence, Italy;Dipartimento di Biologia Animale, Università di Torino, Via A. Albertina 17, 10100 Turin, Italy

关键词: Catechol 1;    2-dioxygenase;    Intradiol dioxygenase;    Phenol degradation;    Acinetobacter radioresistens;    Subunit dissociation;    C1;    2O;    catechol 1;    2-dioxygenase;    C2;    3O;    catechol 2;    3-dioxygenase;    EPR;    electron paramagnetic resonance;    SDS-PAGE;    sodium dodecyl sulfate-polyacrylamide gel electrophoresis;   

DOI  :  10.1016/S0014-5793(97)01167-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

A catechol 1,2-dioxygenase (C1,2O) has been purified to homogeneity from Acinetobacter radioresistens grown on phenol as the sole carbon and energy source. The C1,2O appears to be a homodimer, with a molecular mass of 78 000 Da. At relatively high ionic strengths (0.5 M Na₂SO₄) subunit dissociation occurs and the monomeric unit (38 700 Da) is shown to be active. This phenomenon has never been observed before in dioxygenases. The purified C1,2O contains 0.96 iron(III) ions per unit and spectroscopic measurements suggest the presence of one high-spin iron(III) ion in an environment characteristic of intradiol cleaving enzymes. The NH₂-terminal amino acid sequence has been determined and compared to the primary structures of intradiol rings cleaving dioxygenases from other Acinetobacter strains revealing 45% homology with the benzoate-grown A. calcoaceticus ADP-1 and an identity of only one of the 20 amino acids sequenced for the phenol-grown A. calcoaceticus NCIB 8250.

【 授权许可】

Unknown