Structural and functional comparison of fumarylacetoacetate domain containing protein 1 in human and mouse

Alexander K.H Weiss,Pidder Jansen-Dürr,Jill Von Velsen,Christina Metzger,Lorenza Mottes,Matthew W Bowler,Bernhard Rupp,Max Holzknecht,Elia Cappuccio,Andreas Naschberger

doi:10.1042/bsr20194431

Abstract

FAH domain containing protein 1 (FAHD1) is a mammalian mitochondrial protein, displaying bifunctionality as acylpyruvate hydrolase (ApH) and oxaloacetate decarboxylase (ODx) activity. We report the crystal structure of mouse FAHD1 and structural mapping of the active site of mouse FAHD1. Despite high structural similarity with human FAHD1, a rabbit monoclonal antibody (RabMab) could be produced that is able to recognize mouse FAHD1, but not the human form, whereas a polyclonal antibody recognized both proteins. Epitope mapping in combination with our deposited crystal structures revealed that the epitope overlaps with a reported SIRT3 deacetylation site in mouse FAHD1.

Highlights

The superfamily of fumarylacetoacetate hydrolase (FAH) proteins describes enzymes that share a conserved catalytic center, yet exhibit multifunctionality in prokaryotes and eukaryotes [1]
Using oxalate as competitive oxaloacetate decarboxylase (ODx) inhibitor [6,7], complexed and native crystal structure models of recombinant mouse FAHD1 (mFAHD1) were obtained, and structure factors and refined structure models have been deposited with the PDB (6SBI, 6SBJ) (Table 1)
Similar to the crystal structures of human FAHD1 protein (hFAHD1) (6FOG, 6FOH), N-terminal residues are disordered in both models, but ligand-associated conformational differences are present in the complexed structure [6] (Figure 1A), and are similar among the four proteins in the asymmetric unit (ASU)

Summary

Introduction

The superfamily of fumarylacetoacetate hydrolase (FAH) proteins describes enzymes that share a conserved catalytic center, yet exhibit multifunctionality in prokaryotes and eukaryotes [1]. Whereas many distinct FAH superfamily members were described in prokaryotes [1], the only identified members in eukaryotes are FAH and FAH domain containing proteins 1 and 2 (FAHD1 and FAHD2) [1–3]. The structural basis for the bifunctionally of the human protein, i.e., ODx and acylpyruvate hydrolase (ApH), was recently described [6]. Epitope mapping in combination with our deposited crystal structures revealed the epitope recognized by RabMab 27-1, which overlaps with a reported SIRT3 deacetylation site in FAHD1. Potential implications of these findings are discussed below

Methods

Results

Conclusion