Structural and functional analysis of a dimeric fumarylacetoacetate hydrolase (EaFAH) from psychrophilic Exiguobacterium antarcticum

Abstract

Fumarylacetoacetate hydrolase (FAH) is essential for the degradation of aromatic amino acids as well as for the cleavage of carbon-carbon bonds in metabolites or small organic compounds. Here, the X-ray crystal structure of EaFAH, a dimeric fumarylacetoacetate hydrolase from Exiguobacterium antarcticum, was determined, and its functional properties were investigated using biochemical methods. EaFAH adopts a mixed beta-sandwich roll fold with a highly flexible lid region (Val(73)-Leu(94)), and an Mg2+ ion is bound at the active site by coordinating to the three carboxylate oxygen atoms of Glu(124), Glu(126), and Asp(155). The hydrolytic activity of EaFAH toward various substrates, including linalyl acetate was investigated using native polyacrylamide gel electrophoresis, activity staining, gel filtration, circular dichroism spectroscopy, fluorescence, and enzyme assays. (C) 2019 Elsevier Inc. All rights reserved.