Abstract
Cell extracts of Sphingomonas herbicidovorans MH grown on (R)-mecoprop contained an enzyme activity that selectively converted (R)-mecoprop to 4-chloro-2-methylphenol, whereas extracts of cells grown on (S)-mecoprop contained an enzyme activity selective for the S enantiomer. Both reactions were dependent on alpha-ketoglutarate and ferrous ions. Besides 4-chloro-2-methylphenol, pyruvate and succinate were detected as products of the reactions. Labeling experiments with (18)O2 revealed that both enzyme activities catalyzed a dioxygenation reaction. One of the oxygen atoms of pyruvate and one of the oxygen atoms of succinate were derived from molecular oxygen. Analysis of cell extracts obtained from cells grown on different substrates by sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that growth on (R)-mecoprop and (S)-mecoprop caused the appearance of prominent protein bands at 34 and 32 kDa, respectively. Both protein bands were present when cells grew on the racemic mixture. The results demonstrate that S. herbicidovorans initiated the degradation of each enantiomer of mecoprop by a specific alpha-ketoglutarate-dependent dioxygenase. By comparing conversion rates of various phenoxy herbicides, we confirmed that the two enzyme activities were distinct from that of TfdA, which catalyzes the first step in the degradation of 2,4-dichlorophenoxyacetic acid in Ralstonia eutropha JMP134.
Full Text
The Full Text of this article is available as a PDF (692.0 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Armstrong D. W., Reid G. L., 3rd, Hilton M. L., Chang C. D. Relevance of enantiomeric separations in environmental science. Environ Pollut. 1993;79(1):51–58. doi: 10.1016/0269-7491(93)90177-p. [DOI] [PubMed] [Google Scholar]
- Danganan C. E., Shankar S., Ye R. W., Chakrabarty A. M. Substrate diversity and expression of the 2,4,5-trichlorophenoxyacetic acid oxygenase from Burkholderia cepacia AC1100. Appl Environ Microbiol. 1995 Dec;61(12):4500–4504. doi: 10.1128/aem.61.12.4500-4504.1995. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Daubaras D. L., Hershberger C. D., Kitano K., Chakrabarty A. M. Sequence analysis of a gene cluster involved in metabolism of 2,4,5-trichlorophenoxyacetic acid by Burkholderia cepacia AC1100. Appl Environ Microbiol. 1995 Apr;61(4):1279–1289. doi: 10.1128/aem.61.4.1279-1289.1995. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fukumori F., Hausinger R. P. Alcaligenes eutrophus JMP134 "2,4-dichlorophenoxyacetate monooxygenase" is an alpha-ketoglutarate-dependent dioxygenase. J Bacteriol. 1993 Apr;175(7):2083–2086. doi: 10.1128/jb.175.7.2083-2086.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fukumori F., Hausinger R. P. Purification and characterization of 2,4-dichlorophenoxyacetate/alpha-ketoglutarate dioxygenase. J Biol Chem. 1993 Nov 15;268(32):24311–24317. [PubMed] [Google Scholar]
- Hanauske-Abel H. M., Günzler V. A stereochemical concept for the catalytic mechanism of prolylhydroxylase: applicability to classification and design of inhibitors. J Theor Biol. 1982 Jan 21;94(2):421–455. doi: 10.1016/0022-5193(82)90320-4. [DOI] [PubMed] [Google Scholar]
- Horvath M., Ditzelmüller G., Loidl M., Streichsbier F. Isolation and characterization of a 2-(2,4-dichlorophenoxy) propionic acid-degrading soil bacterium. Appl Microbiol Biotechnol. 1990 May;33(2):213–216. doi: 10.1007/BF00176527. [DOI] [PubMed] [Google Scholar]
- Hur H., Newman L. M., Wackett L. P., Sadowsky M. J. Toluene 2-Monooxygenase-Dependent Growth of Burkholderia cepacia G4/PR1 on Diethyl Ether. Appl Environ Microbiol. 1997 Apr;63(4):1606–1609. doi: 10.1128/aem.63.4.1606-1609.1997. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Häggblom M. M. Microbial breakdown of halogenated aromatic pesticides and related compounds. FEMS Microbiol Rev. 1992 Sep;9(1):29–71. doi: 10.1111/j.1574-6968.1992.tb05823.x. [DOI] [PubMed] [Google Scholar]
- Kohler H. P., Schmid A., van der Maarel M. Metabolism of 2,2'-dihydroxybiphenyl by Pseudomonas sp. strain HBP1: production and consumption of 2,2',3-trihydroxybiphenyl. J Bacteriol. 1993 Mar;175(6):1621–1628. doi: 10.1128/jb.175.6.1621-1628.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Merkler D. J., Kulathila R., Consalvo A. P., Young S. D., Ash D. E. 18O isotopic 13C NMR shift as proof that bifunctional peptidylglycine alpha-amidating enzyme is a monooxygenase. Biochemistry. 1992 Aug 18;31(32):7282–7288. doi: 10.1021/bi00147a011. [DOI] [PubMed] [Google Scholar]
- Roach P. L., Clifton I. J., Fülöp V., Harlos K., Barton G. J., Hajdu J., Andersson I., Schofield C. J., Baldwin J. E. Crystal structure of isopenicillin N synthase is the first from a new structural family of enzymes. Nature. 1995 Jun 22;375(6533):700–704. doi: 10.1038/375700a0. [DOI] [PubMed] [Google Scholar]
- Simoni S., Klinke S., Zipper C., Angst W., Kohler H. E. Enantioselective Metabolism of Chiral 3-Phenylbutyric Acid, an Intermediate of Linear Alkylbenzene Degradation, by Rhodococcus rhodochrous PB1. Appl Environ Microbiol. 1996 Mar;62(3):749–755. doi: 10.1128/aem.62.3.749-755.1996. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Smith A. E. Identification of 4-chloro-2-methylphenol as a soil degradation product of ring-labelled [14C]mecoprop. Bull Environ Contam Toxicol. 1985 May;34(5):656–660. doi: 10.1007/BF01609789. [DOI] [PubMed] [Google Scholar]
- Xun L., Wagnon K. B. Purification and Properties of Component B of 2,4,5-Trichlorophenoxyacetate Oxygenase from Pseudomonas cepacia AC1100. Appl Environ Microbiol. 1995 Sep;61(9):3499–3502. doi: 10.1128/aem.61.9.3499-3502.1995. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zipper C., Nickel K., Angst W., Kohler H. P. Complete microbial degradation of both enantiomers of the chiral herbicide mecoprop [(RS)-2-(4-chloro-2-methylphenoxy)propionic acid] in an enantioselective manner by Sphingomonas herbicidovorans sp. nov. Appl Environ Microbiol. 1996 Dec;62(12):4318–4322. doi: 10.1128/aem.62.12.4318-4322.1996. [DOI] [PMC free article] [PubMed] [Google Scholar]