1Q4U

Crystal structure of 4-hydroxybenzoyl CoA thioesterase from arthrobacter sp. strain SU complexed with 4-hydroxybenzyl CoA

Summary for 1Q4U

• Entry DOI: 10.2210/pdb1q4u/pdb
• Related: 1Q4S 1Q4T
• Descriptor: Thioesterase, 4-HYDROXYBENZYL COENZYME A, 1,2-ETHANEDIOL, ... (4 entities in total)
• Functional Keywords: thioesterase, hot-dog, hydrolase
• Biological source: Arthrobacter sp.
• Total number of polymer chains: 2
• Total formula weight: 34642.24

Authors

Thoden, J.B.,Zhuang, Z.,Dunaway-Mariano, D.,Holden, H.M. (deposition date: 2003-08-04, release date: 2003-09-23, Last modification date: 2023-08-16)

Primary citation

Thoden, J.B.,Zhuang, Z.,Dunaway-Mariano, D.,Holden, H.M.
The Structure of 4-Hydroxybenzoyl-CoA Thioesterase from Arthrobacter sp. strain SU
J.Biol.Chem., 278:43709-43716, 2003

PubMed Abstract: The 4-chlorobenzoyl-CoA dehalogenation pathway in certain Arthrobacter and Pseudomonas bacterial species contains three enzymes: a ligase, a dehalogenase, and a thioesterase. Here we describe the high resolution x-ray crystallographic structure of the 4-hydroxybenzoyl-CoA thioesterase from Arthrobacter sp. strain SU. The tetrameric enzyme is a dimer of dimers with each subunit adopting the so-called "hot dog fold" composed of six strands of anti-parallel beta-sheet flanked on one side by a rather long alpha-helix. The dimers come together to form the tetramer with their alpha-helices facing outwards. This quaternary structure is in sharp contrast to that previously observed for the 4-hydroxybenzoyl-CoA thioesterase from Pseudomonas species strain CBS-3, whereby the dimers forming the tetramer pack with their alpha-helices projecting toward the interfacial region. In the Arthrobacter thioesterase, each of the four active sites is formed by three of the subunits of the tetramer. On the basis of both structural and kinetic data, it appears that Glu73 is the active site base in the Arthrobacter thioesterase. Remarkably, this residue is located on the opposite side of the substrate-binding pocket compared with that observed for the Pseudomonas enzyme. Although these two bacterial thioesterases demonstrate equivalent catalytic efficiencies, substrate specificities, and metabolic functions, their quaternary structures, CoA-binding sites, and catalytic platforms are decidedly different.

PubMed: 12907670
DOI: 10.1074/jbc.M308198200

Experimental method

X-RAY DIFFRACTION (1.6 Å)