The toxicological significance of inhibition of MAAI is highlighted by the consequences of loss of function mutations in fumarylacetoacetate
(FAA) hydrolase, the terminal enzyme of phenylalanine and tyrosine catabolism.
Fernandez-Canon and Penalva (1998) have reported the Zeta GSTs in Aspergillus nidulans and humans are identical to an enzyme maleylacetoacetate isomerase (MAAI), which catalyzes the glutathione-dependent cis--trans isomerization of maleylacetoacetate to fumarylacetoacetate in the catabolic pathway of tyrosine/phenylalanine.
The first three-dimensional structure of a Zeta class GST has been characterized from Arabidopsis, which differs catalytically from previously characterised GSTs in that it adds glutathione reversibly to the cis double bond of maleylacetoacetate, allowing bond rotation before elimination of glutathione to yield fumarylacetoacetate, as those with Aspergillus nidulans and human (Thom et al.
Tyrosinemia type I (TYR 1;  OMIM 276700) is caused by autosomal recessive fumarylacetoacetate
hydrolase (EC 3.
Tyrosinemia is a genetic inborn error of metabolism, involving the amino acid tyrosine and is associated with a lack of the enzyme Fumarylacetoacetate
A single cell had apparently reverted to producing the missing enzyme, fumarylacetoacetate
hydrolase (FAH), and then vigorously proliferated to generate each nodule.
The enzyme is fumarylacetoacetate hydrolase (FAH) which is markedly reduced in affected patients.
Prenatal diagnosis is possible and can be performed by measuing succinylacetone in the amniotic fluid or fumarylacetoacetate hydrolase (FAH) in amniotic fluid cells.
Blas Cerda, director of Clinical Tandem Mass Spectrometry R&D at PerkinElmer, and co-developer of the NeoBase Kit, noted, "Tyrosinemia Type I is caused by a deficiency in the enzyme fumarylacetoacetate
hydrolase, and its incidence is estimated at approximately one in 100,000 to 120,000 newborns.
Specifically, GST-[xi] metabolizes MAA to fumarylacetoacetate
(FAA), which displays apoptogenic, mutagenic, aneugenic, and mitogenic activities (Bergeron et al.
Tyrosinemia type I is caused by a deficiency of the enzyme fumarylacetoacetate
hydrolase (EC 3.