The three-dimensional structure of 4-hydroxybenzoyl-CoA thioesterase from Pseudomonas sp. Strain CBS-3.
The soil-dwelling microbe, Pseudomonas sp. strain CBS-3, has attracted recent attention due to its ability to survive on 4-chlorobenzoate as its sole carbon source. The biochemical pathway by which this organism converts 4-chlorobenzoate to 4-hydroxybenzoate consists of three enzymes: 4-chlorobenzoyl-CoA ligase, 4-chlorobenzoyl-CoA dehalogenase, and 4-hydroxybenzoyl-CoA thioesterase. Here we describe the three-dimensional structure of the thioesterase determined to 2.0-A resolution. Each subunit of the homotetramer is characterized by a five-stranded anti-parallel beta-sheet and three major alpha-helices. While previous amino acid sequence analyses failed to reveal any similarity between this thioesterase and other known proteins, the results from this study clearly demonstrate that the molecular architecture of 4-hydroxybenzoyl-CoA thioesterase is topologically equivalent to that observed for beta-hydroxydecanoyl thiol ester dehydrase from Escherichia coli. On the basis of the structural similarity between these two enzymes, the active site of the thioesterase has been identified and a catalytic mechanism proposed.
Benning
M M
MM
Department of Biochemistry, College of Agricultural and Life Sciences, University of Wisconsin- Madison, Madison, Wisconsin 53705, USA.
Wesenberg
G
G
Liu
R
R
Taylor
K L
KL
Dunaway-Mariano
D
D
Holden
H M
HM
D000595:Amino Acid Sequence; D001224:Aspartic Acid / Q000737:chemistry / Q000378:metabolism; D001665:Binding Sites; D002384:Catalysis; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D011549:Pseudomonas / Q000201:enzymology*; D017386:Sequence Homology, Amino Acid; D013869:Thiolester Hydrolases / Q000737:chemistry* / Q000378:metabolism
D001224:Aspartic Acid; C092167:4-hydroxybenzoyl-CoA hydrolase; D013869:Thiolester Hydrolases