5xr2 | pdb_00005xr2
SAV0551
Structural highlights
FunctionHCHA_STAAM Protein and nucleotide deglycase that catalyzes the deglycation of the Maillard adducts formed between amino groups of proteins or nucleotides and reactive carbonyl groups of glyoxals. Thus, functions as a protein deglycase that repairs methylglyoxal- and glyoxal-glycated proteins, and releases repaired proteins and lactate or glycolate, respectively. Deglycates cysteine, arginine and lysine residues in proteins, and thus reactivates these proteins by reversing glycation by glyoxals. Acts on early glycation intermediates (hemithioacetals and aminocarbinols), preventing the formation of Schiff bases and advanced glycation endproducts (AGE). Also functions as a nucleotide deglycase able to repair glycated guanine in the free nucleotide pool (GTP, GDP, GMP, dGTP) and in DNA and RNA. Is thus involved in a major nucleotide repair system named guanine glycation repair (GG repair), dedicated to reversing methylglyoxal and glyoxal damage via nucleotide sanitization and direct nucleic acid repair. Plays an important role in protecting cells from carbonyl stress. Publication Abstract from PubMedThe DJ-1/ThiJ/PfpI superfamily of proteins is highly conserved across all biological kingdoms showing divergent multi-functions, such as chaperone, catalase, protease, and kinase. The common theme of these functions is responding to and managing various cellular stresses. DJ-1/ThiJ/PfpI superfamily members are classified into three subfamilies according to their quaternary structure (DJ-1-, YhbO-, and Hsp-types). The Hsp-type subfamily includes Hsp31, a chaperone and glyoxalase III. SAV0551, an Hsp-type subfamily member from Staphylococcus aureus, is a hypothetical protein that is predicted as Hsp31. Thus, to reveal the function and reaction mechanism of SAV0551, the crystal structure of SAV0551 was determined. The overall folds in SAV0551 are similar to other members of the Hsp-type subfamily. We have shown that SAV0551 functions as a chaperone and that the surface structure is crucial for holding unfolded substrates. As many DJ-1/ThiJ/PfpI superfamily proteins have been characterized as glyoxalase III, our study also demonstrates SAV0551 as a glyoxalase III that is independent of any cofactors. The reaction mechanism was evaluated via a glyoxylate-bound structure that mimics the hemithioacetal reaction intermediate. We have confirmed that the components required for reaction are present in the structure, including a catalytic triad for a catalytic action, His78 as a base, and a water molecule for hydrolysis. Our functional studies based on the crystal structures of native and glyoxylate-bound SAV0551 will provide a better understanding of the reaction mechanism of a chaperone and glyoxalase III. Structural and functional studies of SAV0551 from Staphylococcus aureus as a chaperone and glyoxalase III.,Kim HJ, Lee KY, Kwon AR, Lee BJ Biosci Rep. 2017 Oct 18. pii: BSR20171106. doi: 10.1042/BSR20171106. PMID:29046369[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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