Publication Date:
1991-07-12
Description:
Microbial enzyme systems may be used in the biodegradation of persistent environmental pollutants. The three polypeptide components of one such system, the 4-chlorobenzoate dehalogenase system, have been isolated, and the chemical steps of the 4-hydroxybenzoate-forming reaction that they catalyze have been identified. The genes contained within a 4.5-kilobase Pseudomonas sp. strain CBS3 chromosomal DNA fragment that encode dehalogenase activity were selectively expressed in transformed Escherichia coli. Oligonucleotide sequencing revealed a stretch of homology between the 57-kilodalton (kD) polypeptide and several magnesium adenosine triphosphate (MgATP)-cleaving enzymes that allowed MgATP and coenzyme A (CoA) to be identified as the dehalogenase cosubstrate and cofactor, respectively. The dehalogenase activity arises from two components, a 4-chlorobenzoate:CoA ligase-dehalogenase (an alpha beta dimer of the 57- and 30-kD polypeptides) and a thioesterase (the 16-kD polypeptide).〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Scholten, J D -- Chang, K H -- Babbitt, P C -- Charest, H -- Sylvestre, M -- Dunaway-Mariano, D -- GM 28688/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1991 Jul 12;253(5016):182-5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry and Biochemistry, University of Maryland, College Park 20742.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1853203" target="_blank"〉PubMed〈/a〉
Keywords:
Adenosine Triphosphate/metabolism
;
Amino Acid Sequence
;
Cell-Free System
;
Chlorobenzoates/*metabolism
;
Cloning, Molecular
;
Coenzyme A/metabolism
;
DNA, Bacterial/genetics
;
Genes, Bacterial
;
Hydrolases/*genetics/metabolism
;
Hydrolysis
;
Molecular Sequence Data
;
Pseudomonas/*enzymology/*genetics
;
Restriction Mapping
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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