title: Human lysosomal DNase IIalpha contains two requisite PLD-signature (HxK) motifs: evidence for a pseudodimeric structure of the active enzyme species.
abstract: Lysosomal DNase IIalpha is essential for DNA waste removal and auxiliary apoptotic DNA fragmentation in higher eukaryotes. Despite the key role of this enzyme, little is known about its structure-function relationships. Here, mutational and biochemical analyses were used to characterize human DNase IIalpha variants expressed in mammalian cells. The resulting data strongly support the hypothesis that the enzyme is a monomeric phospholipase D-family member with a pseudodimeric protein fold. According to our results, DNase IIalpha contains two requisite PLD-signature motifs ((113)HTK(115) and (295)HSK(297)) in the N- and C-terminal subdomains, respectively, that together form a single active site. Based on these data, we present an experimentally validated structural model of DNase IIalpha.
authors.affiliation: Institute of Biochemistry, Justus-Liebig-University Giessen, Germany.
authors.forename: Patrick
authors.initials: P
authors.lastname: Schäfer
authors.forename: Iwona A
authors.initials: IA
authors.lastname: Cymerman
authors.forename: Janusz M
authors.initials: JM
authors.lastname: Bujnicki
authors.forename: Gregor
authors.initials: G
authors.lastname: Meiss
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D020134:Catalytic Domain; D004706:Endodeoxyribonucleases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D008247:Lysosomes / Q000201:enzymology; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011487:Protein Conformation; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
chemical_list: D011994:Recombinant Proteins; D004706:Endodeoxyribonucleases; C019329:deoxyribonuclease II