Ancestry of the 4-chlorobenzoate dehalogenase: analysis of amino acid sequence identities among families of acyl:adenyl ligases, enoyl-CoA hydratases/isomerases, and acyl-CoA thioesterases.
We have deduced the nucleotide sequence of the genes encoding the three components of 4-chlorobenzoate (4-CBA) dehalogenase from Pseudomonas sp. CBS-3 and examined the origin of these proteins by homology analysis. Open reading frame 1 (ORF1) encodes a 30-kDa 4-CBA-coenzyme A dehalogenase related to enoyl-coenzyme A hydratases functioning in fatty acid beta-oxidation. ORF2 encodes a 57-kDa protein which activates 4-CBA by acyl adenylation/thioesterification. This 4-CBA:coenzyme A ligase shares significant sequence similarity with a large group of proteins, many of which catalyze similar chemistry in beta-oxidation pathways or in siderophore and antibiotic synthetic pathways. These proteins have in common a short stretch of sequence, (T,S)(S,G)G(T,S)(T,E)G(L,X)PK(G,-), which is particularly highly conserved and which may represent an important new class of "signature" sequence. We were unable to find any proteins homologous in sequence to the 16-kDa 4-hydroxybenzoate-coenzyme A thioesterase encoded by ORF3. Analysis of the chemistry and function of the proteins found to be structurally related to the 4-CBA:coenzyme A ligase and the 4-CBA-coenzyme A dehalogenase supports the proposal that they evolved from a beta-oxidation pathway.
Babbitt
P C
PC
Department of Pharmaceutical Chemistry, University of California, San Francisco 94143.
Kenyon
G L
GL
Martin
B M
BM
Charest
H
H
Slyvestre
M
M
Scholten
J D
JD
Chang
K H
KH
Liang
P H
PH
Dunaway-Mariano
D
D
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D005798:Genes, Bacterial; D006867:Hydrolases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008025:Ligases / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D010170:Palmitoyl-CoA Hydrolase / Q000737:chemistry / Q000235:genetics*; D011549:Pseudomonas / Q000201:enzymology*; D016415:Sequence Alignment
D006867:Hydrolases; D010170:Palmitoyl-CoA Hydrolase; C042846:4-chlorobenzoate dehalogenase; D008025:Ligases