Analysis of genes encoding the 2,4-dichlorophenoxyacetic acid-degrading enzyme from Sphingomonas agrestis 58-1
A 2,4-dichlorophenoxy acetic acid (2,4-D)-degrading bacterium, strain 58-1, was newly isolated from soil samples collected in the Fukuoka Prefecture, Japan, and grown on an enrichment culture medium containing 2,4-D as the sole carbon source. Phylogenic analysis identified strain 58-1 as Sphingomona...
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Published in | Journal of bioscience and bioengineering Vol. 108; no. 1; pp. 56 - 59 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
Amsterdam
Elsevier B.V
01.07.2009
Elsevier |
Subjects | |
Online Access | Get full text |
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Summary: | A 2,4-dichlorophenoxy acetic acid (2,4-D)-degrading bacterium, strain 58-1, was newly isolated from soil samples collected in the Fukuoka Prefecture, Japan, and grown on an enrichment culture medium containing 2,4-D as the sole carbon source. Phylogenic analysis identified strain 58-1 as
Sphingomonas agrestis. In 2,4-D degraders, classes I, II, and III inherit the
tfdA,
cadA, and
tfdAα genes, respectively, and the results from degenerate-PCR indicated that this strain belongs to the class II degraders. A clone that includes the
cadA gene homolog of
S. agrestis 58-1 was screened from a library by using the PCR amplified fragment as a DNA probe. The cloned fragment was sequenced and found to consist of 5043 nucleotides and include 3 open reading frames (orfs). The
orf1,
orf2, and
orf3 genes encode polypeptides consisting of 412, 448, and 177 amino acids, respectively. The
Orf2 product shares a high degree of sequence similarity (92%) with the large subunit of 2,4-D oxygenase from the
Bradyrhizobium sp. strain HW13, which belongs to the class III 2,4-D degraders, while the
orf3 product shared 63% sequence similarity with the small subunit of 2,4-D oxygenase from the strain HW13. The results of the functional expression analysis using various deletion mutants in
Escherichia coli revealed that the expression of both
orf2 and
orf3 genes, but not
orf1, is essential for the conversion of 2,4-D to 2,4-DCP. From these results, we conclude the first isolation of 2,4-D oxygenase genes from a class II 2,4-D degrader. |
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Bibliography: | 2009005488 F30 ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 ObjectType-Article-1 ObjectType-Feature-2 |
ISSN: | 1389-1723 1347-4421 |
DOI: | 10.1016/j.jbiosc.2009.02.018 |