1q7l
From Proteopedia
Zn-binding domain of the T347G mutant of human aminoacylase-I
Structural highlights
Disease[ACY1_HUMAN] Defects in ACY1 are the cause of aminoacylase-1 deficiency (ACY1D) [MIM:609924]. ACY1D results in a metabolic disorder manifesting with encephalopathy, unspecific psychomotor delay, psychomotor delay with atrophy of the vermis and syringomyelia, marked muscular hypotonia or normal clinical features. Epileptic seizures are a frequent feature. All affected individuals exhibit markedly increased urinary excretion of several N-acetylated amino acids.[1] [2] [3] [4] Function[ACY1_HUMAN] Involved in the hydrolysis of N-acylated or N-acetylated amino acids (except L-aspartate).[5] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedMembers of the aminoacylase-1 (Acy1)/M20 family of aminoacylases and exopeptidases exist as either monomers or homodimers. They contain a zinc-binding domain and a second domain mediating dimerization in the latter case. The roles that both domains play in catalysis have been investigated for human Acy1 (hAcy1) by x-ray crystallography and by site-directed mutagenesis. Structure comparison of the dinuclear zinc center in a mutant of hAcy1 reported here with dizinc centers in related enzymes points to a difference in zinc ligation in the Acy1/M20 family. Mutational analysis supports catalytic roles of zinc ions, a vicinal glutamate, and a histidine from the dimerization domain. By complementing different active site mutants of hAcy1, we show that catalysis occurs at the dimer interface. Reinterpretation of the structure of a monomeric homolog, peptidase V, reveals that a domain insertion mimics dimerization. We conclude that monomeric and dimeric Acy1/M20 family members share a unique active site architecture involving both enzyme domains. The study may provide means to improve homologous carboxypeptidase G2 toward application in antibody-directed enzyme prodrug therapy. Essential roles of zinc ligation and enzyme dimerization for catalysis in the aminoacylase-1/M20 family.,Lindner HA, Lunin VV, Alary A, Hecker R, Cygler M, Menard R J Biol Chem. 2003 Nov 7;278(45):44496-504. Epub 2003 Aug 21. PMID:12933810[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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