These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Pseudomonas aeruginosa 142 uses a three-component ortho-halobenzoate 1,2-dioxygenase for metabolism of 2,4-dichloro- and 2-chlorobenzoate.
    Author: Romanov V, Hausinger RP.
    Journal: J Bacteriol; 1994 Jun; 176(11):3368-74. PubMed ID: 8195093.
    Abstract:
    Cell extracts of Pseudomonas aeruginosa 142, which was previously isolated from a polychlorinated biphenyl-degrading consortium, were shown to degrade 2,4-dichlorobenzoate, 2-chlorobenzoate, and a variety of other substituted ortho-halobenzoates by a reaction that requires oxygen, NADH, Fe(II), and flavin adenine dinucleotide. By using extracts that were chromatographically depleted of chlorocatechol and catechol 1,2-dioxygenase activities, products of the initial reaction with 2,4- or 2,5-dichlorobenzoate and 2-chlorobenzoate were identified by mass spectrometry as 4-chlorocatechol and catechol. In contrast to the well-characterized benzoate dioxygenases or the recently described 2-halobenzoate 1,2-dioxygenase from P. cepacia 2CBS (S. Fetzner, R. Müller, and F. Lingens, J. Bacteriol. 174:279-290, 1992) that possess two protein components, the P. aeruginosa enzyme was resolved by ion-exchange chromatography into three components, each of which is required for activity. To verify the distinct nature of this enzyme, we purified, characterized, and identified one component as a ferredoxin (M(r), approximately 13,000) containing a single [2Fe-2S] Rieske-type cluster (electron paramagnetic resonance spectroscopic values of gx = 1.82, gy = 1.905, and gz = 2.02 in the reduced state) that is related in sequence to ferredoxins found in the naphthalene and biphenyl three-component dioxygenase systems. By analogy to these enzymes, we propose that the P. aeruginosa ferredoxin serves as an electron carrier between an NADH-dependent ferredoxin reductase and the terminal component of the ortho-halobenzoate 1,2-dioxygenase. The broad specificity and high regiospecificity of the enzyme make it a promising candidate for use in the degradation of mixtures of chlorobenzoates.
    [Abstract] [Full Text] [Related] [New Search]