title: Identification of an artificial peptide motif that binds and stabilizes reduced human DJ-1.
abstract: Although the precise biochemical function of DJ-1 remains unclear, it has been found to exert cytoprotective activity against oxidative stress. Cys106 is central to this function since it has a distinctly low pK(a) rendering it extremely susceptible for oxidation. This characteristic, however, also poses a severe hindrance to obtain reduced DJ-1 for in vitro investigation. We have developed an approach to produce recombinant human DJ-1 in its reduced form as a bona fide basis for exploring the redox capacities of the protein. We solved the crystal structure of this DJ-1 at 1.56Å resolution, allowing us to capture Cys106 in the reduced state for the first time. The dimeric structure reveals one molecule of DJ-1 in its reduced state while the other exhibits the characteristics of a mono-oxygenated cysteine. Comparison with previous structures indicates the absence of redox dependent global conformational changes in DJ-1. The capture of reduced Cys106 is facilitated by stabilization within the putative active site achieved through a glutamate side chain. This side chain is provided by a crystallographic neighbor as part of a 'Leu-Glu' motif, which was added to the C-terminus of DJ-1. In the structure this motif binds DJ-1 in close proximity to Cys106 through extended hydrophilic and hydrophobic interactions depicting a distinct binding pocket, which can serve as a basis for compound development targeting DJ-1.
authors: Cancer Center, Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA.
authors: Lakshmanane
authors: L
authors: Premkumar
authors: Małgorzata K
authors: MK
authors: Dobaczewska
authors: Stefan J
authors: SJ
authors: Riedl
mesh_terms: D020816:Amino Acid Motifs; D001665:Binding Sites; D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D003545:Cysteine / Q000737:chemistry*; D005973:Glutamine / Q000737:chemistry; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000737:chemistry*; D007930:Leucine / Q000737:chemistry; D015513:Oncogene Proteins / Q000737:chemistry*; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry*; D011485:Protein Binding; D000071617:Protein Deglycase DJ-1; D055550:Protein Stability; D017382:Reactive Oxygen Species / Q000737:chemistry; D011994:Recombinant Proteins / Q000737:chemistry
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D015513:Oncogene Proteins; D010455:Peptides; D017382:Reactive Oxygen Species; D011994:Recombinant Proteins; D005973:Glutamine; C105131:PARK7 protein, human; D000071617:Protein Deglycase DJ-1; D007930:Leucine; D003545:Cysteine