2aij
Formylglycine generating enzyme C336S mutant covalently bound to substrate peptide CTPSR
Structural highlights
DiseaseSUMF1_HUMAN Defects in SUMF1 are the cause of multiple sulfatase deficiency (MSD) [MIM:272200. MSD is a clinically and biochemically heterogeneous disorder caused by the simultaneous impairment of all sulfatases, due to defective post-translational modification and activation. It combines features of individual sulfatase deficiencies such as metachromatic leukodystrophy, mucopolysaccharidosis, chondrodysplasia punctata, hydrocephalus, ichthyosis, neurologic deterioration and developmental delay. Inheritance is autosomal recessive.[1] [2] [3] [4] FunctionSUMF1_HUMAN Using molecular oxygen and an unidentified reducing agent, oxidizes a cysteine residue in the substrate sulfatase to an active site 3-oxoalanine residue, which is also called C(alpha)-formylglycine. Known substrates include GALNS, ARSA, STS and ARSE.[5] [6] 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 PubMedThe formylglycine (FGly)-generating enzyme (FGE) uses molecular oxygen to oxidize a conserved cysteine residue in all eukaryotic sulfatases to the catalytically active FGly. Sulfatases degrade and remodel sulfate esters, and inactivity of FGE results in multiple sulfatase deficiency, a fatal disease. The previously determined FGE crystal structure revealed two crucial cysteine residues in the active site, one of which was thought to be implicated in substrate binding. The other cysteine residue partakes in a novel oxygenase mechanism that does not rely on any cofactors. Here, we present crystal structures of the individual FGE cysteine mutants and employ chemical probing of wild-type FGE, which defined the cysteines to differ strongly in their reactivity. This striking difference in reactivity is explained by the distinct roles of these cysteine residues in the catalytic mechanism. Hitherto, an enzyme-substrate complex as an essential cornerstone for the structural evaluation of the FGly formation mechanism has remained elusive. We also present two FGE-substrate complexes with pentamer and heptamer peptides that mimic sulfatases. The peptides isolate a small cavity that is a likely binding site for molecular oxygen and could host reactive oxygen intermediates during cysteine oxidation. Importantly, these FGE-peptide complexes directly unveil the molecular bases of FGE substrate binding and specificity. Because of the conserved nature of FGE sequences in other organisms, this binding mechanism is of general validity. Furthermore, several disease-causing mutations in both FGE and sulfatases are explained by this binding mechanism. A general binding mechanism for all human sulfatases by the formylglycine-generating enzyme.,Roeser D, Preusser-Kunze A, Schmidt B, Gasow K, Wittmann JG, Dierks T, von Figura K, Rudolph MG Proc Natl Acad Sci U S A. 2006 Jan 3;103(1):81-6. Epub 2005 Dec 20. PMID:16368756[7] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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