Organization and sequence analysis of the 2,4-dichlorophenol hydroxylase and dichlorocatechol oxidative operons of plasmid pJP4.
Growth of Alcaligenes eutrophus JMP134 on 2,4-dichlorophenoxyacetate requires a 2,4-dichlorphenol hydroxylase encoded by gene tfdB. Catabolism of either 2,4-dichlorophenoxyacetate or 3-chlorobenzoate involves enzymes encoded by the chlorocatechol oxidative operon consisting of tfdCDEF, which converts 3-chloro- and 3,5-dichlorocatechol to maleylacetate and chloromaleylacetate, respectively. Transposon mutagenesis has localized tfdB and tfdCDEF to EcoRI fragment B of plasmid pJP4 (R. H. Don, A. J. Wieghtman, H.-J. Knackmuss, and K. N. Timmis, J. Bacteriol. 161:85-90, 1985). We present the complete nucleotide sequence of tfdB and tfdCDEF contained within a 7,954-base-pair HindIII-SstI fragment from EcoRI fragment B. Sequence and expression analysis of tfdB in Escherichia coli suggested that 2,4-dichlorophenol hydroxylase consists of a single subunit of 65 kilodaltons. The amino acid sequences of proteins encoded by tfdD and tfdE were found to be 63 and 53% identical to those of functionally similar enzymes encoded by clcB and clcD, respectively, from plasmid pAC27 of Pseudomonas putida. P. putida(pAC27) can utilize 3-chlorocatechol but not dichlorinated catechols. A region of DNA adjacent to clcD in pAC27 was found to be 47% identical in amino acid sequence to tfdF, a gene important in catabolizing dichlorocatechols. The region in pAC27 does not appear to encode a protein, suggesting that the absence of a functional trans-chlorodienelactone isomerase may prevent P. putida(pAC27) from utilizing 3,5-dichlorocatechol.
Department of Biochemistry, University of Washington, Seattle 98195.
E J
EJ
Perkins
M P
MP
Gordon
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O
Caceres
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PF
Lurquin
D000421:Alcaligenes / Q000235:genetics*; D000595:Amino Acid Sequence; D001483:Base Sequence; D002396:Catechols / Q000378:metabolism*; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D005798:Genes, Bacterial; D006899:Mixed Function Oxygenases / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009876:Operon; D010084:Oxidation-Reduction; D010957:Plasmids; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid
D002396:Catechols; D004269:DNA, Bacterial; C063909:3,5-dichlorocatechol; D006899:Mixed Function Oxygenases; C034354:2,4-dichlorophenol hydroxylase