Purification, crystallization and preliminary X-ray crystallographic analysis of hydroxycinnamoyl-coenzyme A hydratase-lyase (HCHL), a crotonase homologue active in phenylpropanoid metabolism.

York Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, York YO10 5YW, England.
Acta Crystallographica Section D Biological Crystallography (Impact Factor: 7.23). 01/2005; 60(Pt 12 Pt 2):2343-5. DOI: 10.1107/S0907444904024588
Source: PubMed

ABSTRACT 4-Hydroxycinnamoyl-coenzyme A hydratase-lyase (HCHL), also called feruloyl-CoA hydratase-lyase (FCHL), from Pseudomonas fluorescens strain AN103 is an enzyme of the crotonase superfamily that catalyses the one-step conversion of the CoA thioesters of 4-coumaric acid, caffeic acid and ferulic acid to the aromatic aldehydes 4-hydroxybenzaldehyde, protocatechuic aldehyde and vanillin, respectively. The reaction occurs via a hydration followed by a carbon-carbon bond-cleavage reaction. HCHL has been crystallized by the hanging-drop method of vapour diffusion using polyethylene glycol 20 000 Da as the precipitant. The crystals belong to the orthorhombic system, with proposed space group P2(1)2(1)2 and unit-cell parameters a = 154.2, b = 167.5, c = 130.8 A. The V(M) suggests that the asymmetric unit contains four trimers. Single-wavelength data collection has been undertaken and structure determination is under way by molecular replacement using data collected to 1.8 A resolution. Determination of the structure of HCHL will provide insight into the catalytic mechanism of an unusual enzymatic reaction with relevance to the applications of the enzyme in metabolic engineering.

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