Linked Life Data

11889489

Source:http://linkedlifedata.com/resource/pubmed/id/11889489

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2002-3-12
pubmed:abstractText
In the chlorobenzene degrader Pseudomonas putida GJ31, chlorocatechol is formed as an intermediate and cleaved by a meta-cleavage extradiol chlorocatechol dioxygenase, which has previously been shown to be exceptionally resistant to inactivation by substituted catechols. The gene encoding this dioxygenase ( cbzE) is preceded by a gene ( cbzT) potentially encoding a ferredoxin, the function of which was studied. The cbzT gene product was overproduced in Escherichia coli and purified in recombinant form. Two homologous proteins, CdoT and AtdS, encoded by genes identified in strains degrading nitrobenzene and aniline, respectively, were also purified and characterized. All three proteins showed spectroscopic properties typical for [2Fe-2S] ferredoxins. The chlorocatechol dioxygenase from strain GJ31 (CbzE) was fully inactivated when 4-methylcatechol was used as substrate. Inactivated CbzE could be rapidly reactivated in vitro in the presence of purified CbzT and a source of reductant. It is inferred that the ability of strain GJ31 to metabolize both chlorobenzene and toluene might depend on the regeneration of the chlorocatechol dioxygenase activity mediated by CbzT. Three CbzT-like ferredoxins, including AtdS, were found to be competent in the reactivation of CbzE, whereas XylT, a protein known to mediate reactivation of the catechol dioxygenase from P. putida mt2 (XylE), was ineffective. Accordingly, CbzT formed a covalent complex with CbzE when cross-linked with a carbodiimide, whereas XylT did not. In the reverse situation, CbzT was found to reactivate XylE as efficiently as XylT and formed an heterologous covalent complex with this enzyme upon cross-linking. We conclude that CbzT, CdoT and AtdS are isofunctional ferredoxins that appear to be involved in the reactivation of their cognate catechol dioxygenases. Based on primary structure comparisons, residues of the ferredoxins possibly involved in the molecular interaction with catechol dioxygenases were identified and their significance is discussed.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0302-8933
pubmed:author
pubmed:issnType
Print
pubmed:volume
177
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
345-51
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Ferredoxin-mediated reactivation of the chlorocatechol 2,3-dioxygenase from Pseudomonas putida GJ31.
pubmed:affiliation
Département de Biologie Moléculaire et Structurale/BBSI and CNRS UMR 5092, CEA-Grenoble, France.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't