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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
Pt 1
pubmed:dateCreated
2010-12-27
pubmed:abstractText
Pseudomonas putida F1 cannot grow on styrene despite being able to degrade it through the toluene degradation (tod) pathway. Previous work had suggested that this was because TodF, the meta-fission product (MFP) hydrolase, was unable to metabolize the styrene MFP 2-hydroxy-6-vinylhexa-2,4-dienoate. Here we demonstrate via kinetic and growth analyses that the substrate specificity of TodF is not the limiting factor preventing F1 from growing on styrene. Rather, we found that the metabolite 3-vinylcatechol accumulated during styrene metabolism and that micromolar concentrations of this intermediate inactivated TodE, the catechol-2,3-dioxygenase (C23O) responsible for its cleavage. Analysis of cells growing on styrene suggested that inactivation of TodE and the subsequent accumulation of 3-vinylcatechol resulted in toxicity and cell death. We found that simply overexpressing TodE on a plasmid (pTodE) was all that was necessary to allow F1 to grow on styrene. Similar results were also obtained by expressing a related C23O, DmpB from Pseudomonas sp. CF600, in tandem with its plant-like ferredoxin, DmpQ (pDmpQB). Further analysis revealed that the ability of F1 (pDmpQB) and F1 (pTodE) to grow on styrene correlated with increased C23O activity as well as resistance of the enzyme to 3-vinylcatechol-mediated inactivation. Although TodE inactivation by 3-halocatechols has been studied before, to our knowledge, this is the first published report demonstrating inactivation by a 3-vinylcatechol. Given the ubiquity of catechol intermediates in aromatic hydrocarbon metabolism, our results further demonstrate the importance of C23O inactivation as a determinant of growth substrate specificity.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
1465-2080
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
157
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
89-98
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Growth of Pseudomonas putida F1 on styrene requires increased catechol-2,3-dioxygenase activity, not a new hydrolase.
pubmed:affiliation
Field of Environmental Toxicology, Cornell University Ithaca, NY 14850, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't