title: Structural impact of three Parkinsonism-associated missense mutations on human DJ-1.
abstract: A number of missense mutations in the oxidative stress response protein DJ-1 are implicated in rare forms of familial Parkinsonism. The best-characterized Parkinsonian DJ-1 missense mutation, L166P, disrupts homodimerization and results in a poorly folded protein. The molecular basis by which the other Parkinsonism-associated mutations disrupt the function of DJ-1, however, is incompletely understood. In this study we show that three different Parkinsonism-associated DJ-1 missense mutations (A104T, E163K, and M26I) reduce the thermal stability of DJ-1 in solution by subtly perturbing the structure of DJ-1 without causing major folding defects or loss of dimerization. Atomic resolution X-ray crystallography shows that the A104T substitution introduces water and a discretely disordered residue into the core of the protein, E163K disrupts a key salt bridge with R145, and M26I causes packing defects in the core of the dimer. The deleterious effect of each Parkinsonism-associated mutation on DJ-1 is dissected by analysis of engineered substitutions (M26L, A104V, and E163K/R145E) that partially alleviate each of the defects introduced by the A104T, E163K and M26I mutations. In total, our results suggest that the protective function of DJ-1 can be compromised by diverse perturbations in its structural integrity, particularly near the junctions of secondary structural elements.
authors.affiliation: Department of Biochemistry and the Redox Biology Center, The University of Nebraska-Lincoln, Lincoln, Nebraska 68588-0664, USA.
authors.forename: Mahadevan
authors.initials: M
authors.lastname: Lakshminarasimhan
authors.forename: Marien T
authors.initials: MT
authors.lastname: Maldonado
authors.forename: Wenbo
authors.initials: W
authors.lastname: Zhou
authors.forename: Anthony L
authors.initials: AL
authors.lastname: Fink
authors.forename: Mark A
authors.initials: MA
authors.lastname: Wilson
mesh_terms: D000595:Amino Acid Sequence; D003460:Crystallization; D018360:Crystallography, X-Ray; D019281:Dimerization; D006801:Humans; D006860:Hydrogen Bonding; D047908:Intracellular Signaling Peptides and Proteins / Q000737:chemistry* / Q000235:genetics*; D020125:Mutation, Missense; D015513:Oncogene Proteins / Q000737:chemistry* / Q000235:genetics*; D020734:Parkinsonian Disorders / Q000235:genetics; D000071617:Protein Deglycase DJ-1
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D015513:Oncogene Proteins; C105131:PARK7 protein, human; D000071617:Protein Deglycase DJ-1