This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Skiba, A. Articles by Pieper, D. H. Search for Related Content PubMed PubMed Citation Articles by Skiba, A. Articles by Pieper, D. H.

 Previous Article  |  Next Article 

Journal of Bacteriology, October 2002, p. 5402-5409, Vol. 184, No. 19
0021-9193/02/$04.00+0     DOI: 10.1128/JB.184.19.5402-5409.2002
Copyright © 2002, American Society for Microbiology. All Rights Reserved.

Formation of Protoanemonin from 2-Chloro-cis,cis-Muconate by the Combined Action of Muconate Cycloisomerase and Muconolactone Isomerase

Department of Environmental Microbiology,¹ Department of Biochemical Engineering, German Research Centre for Biotechnology, 38124 Braunschweig, Germany²

Received 22 April 2002/ Accepted 24 June 2002

Muconate cycloisomerases are known to catalyze the reversible conversion of 2-chloro-cis,cis-muconate by 1,4- and 3,6-cycloisomerization into (4S)-(+)-2-chloro- and (4R/5S)-(+)-5-chloromuconolactone. 2-Chloromuconolactone is transformed by muconolactone isomerase with concomitant dechlorination and decarboxylation into the antibiotic protoanemonin. The low k_cat for this compound compared to that for 5-chloromuconolactone suggests that protoanemonin formation is of minor importance. However, since 2-chloromuconolactone is the initially predominant product of 2-chloromuconate cycloisomerization, significant amounts of protoanemonin were formed in reaction mixtures containing large amounts of muconolactone isomerase and small amounts of muconate cycloisomerase. Such enzyme ratios resemble those observed in cell extracts of benzoate-grown cells of Ralstonia eutropha JMP134. In contrast, cis-dienelactone was the predominant product formed by enzyme preparations, in which muconolactone isomerase was in vitro rate limiting. In reaction mixtures containing chloromuconate cycloisomerase and muconolactone isomerase, only minute amounts of protoanemonin were detected, indicating that only small amounts of 2-chloromuconolactone were formed by cycloisomerization and that chloromuconate cycloisomerase actually preferentially catalyzes a 3,6-cycloisomerization.

This article has been cited by other articles:

• Pollmann, K., Wray, V., Pieper, D. H. (2005). Chloromethylmuconolactones as Critical Metabolites in the Degradation of Chloromethylcatechols: Recalcitrance of 2-Chlorotoluene. J. Bacteriol. 187: 2332-2340 [Abstract] [Full Text]  
• Nikodem, P., Hecht, V., Schlomann, M., Pieper, D. H. (2003). New Bacterial Pathway for 4- and 5-Chlorosalicylate Degradation via 4-Chlorocatechol and Maleylacetate in Pseudomonas sp. Strain MT1. J. Bacteriol. 185: 6790-6800 [Abstract] [Full Text]