title: X-ray structure of the Escherichia coli periplasmic 5'-nucleotidase containing a dimetal catalytic site.
abstract: The crystal structure of 5'-nucleotidase (5'-NT) from E. coli, also known as UDP-sugar hydrolase, has been determined at 1.7 A resolution. Two zinc ions are present in the active site, which is located in a cleft between two domains. The dimetal center and a catalytic Asp-His dyad are the main players in the catalytic mechanism. Structure-based sequence comparisons show that the structure also provides a model for animal 5'-NTs, which together with other ectonucleotidases terminate the action of nucleotides as extracellular signaling substances in the nervous system.
authors.affiliation: Institut für Kristallographie, Abteilung Saenger, Freie Universität Berlin, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Knöfel
authors.forename: N
authors.initials: N
authors.lastname: Sträter
mesh_terms: D015720:5'-Nucleotidase / Q000737:chemistry* / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001224:Aspartic Acid / Q000737:chemistry / Q000378:metabolism; D001665:Binding Sites; D002384:Catalysis; D003460:Crystallization; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000201:enzymology*; D006639:Histidine / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D008024:Ligands; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010744:Phosphoric Monoester Hydrolases / Q000737:chemistry; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D015032:Zinc / Q000378:metabolism*
chemical_list: D008024:Ligands; D001224:Aspartic Acid; D006639:Histidine; D010744:Phosphoric Monoester Hydrolases; D015720:5'-Nucleotidase; D015032:Zinc