1ons
From Proteopedia
Crystal structure of Escherichia coli heat shock protein YedU
Structural highlights
Function[HCHA_ECOLI] Functions as a holding molecular chaperone (holdase) which stabilizes unfolding intermediates and rapidly releases them in an active form once stress has abated. Plays an important role in protecting cells from severe heat shock and starvation, as well as in acid resistance of stationary-phase cells. It uses temperature-induced exposure of structured hydrophobic domains to capture and stabilizes early unfolding and denatured protein intermediates under severe thermal stress. Catalyzes the conversion of methylglyoxal (MG) to D-lactate in a single glutathione (GSH)-independent step. It can also use phenylglyoxal as substrate. Glyoxalase activity protects cells against dicarbonyl stress. Displays an aminopeptidase activity that is specific against peptide substrates with alanine or basic amino acids (lysine, arginine) at N-terminus.[1] [2] [3] [4] [5] [6] [7] [8] 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 mRNA of Escherichia coli yedU gene is induced 31-fold upon heat shock. The 31-kD YedU protein, also calls Hsp31, is highly conserved in several human pathogens and has chaperone activity. We solved the crystal structure of YedU at 2.2 A resolution. YedU monomer has an alpha/beta/alpha sandwich domain and a small alpha/beta domain. YedU is a dimer in solution, and its crystal structure indicates that a significant amount of surface area is buried upon dimerization. There is an extended hydrophobic patch that crosses the dimer interface on the surface of the protein. This hydrophobic patch is likely the substrate-binding site responsible for the chaperone activity. The structure also reveals a potential protease-like catalytic triad composed of Cys184, His185, and Asp213, although no enzymatic activity could be identified. YedU coordinates a metal ion using His85, His122, and Glu90. This 2-His-1-carboxylate motif is present in carboxypeptidase A (a zinc enzyme), and a number of dioxygenases and hydroxylases that utilize iron as a cofactor, suggesting another potential function for YedU. The crystal structure of Escherichia coli heat shock protein YedU reveals three potential catalytic active sites.,Zhao Y, Liu D, Kaluarachchi WD, Bellamy HD, White MA, Fox RO Protein Sci. 2003 Oct;12(10):2303-11. PMID:14500888[9] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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