title: Crystal structure of the alkylsulfatase AtsK: insights into the catalytic mechanism of the Fe(II) alpha-ketoglutarate-dependent dioxygenase superfamily.
abstract: The alkylsulfatase AtsK from Pseudomonas putida S-313 belongs to the widespread and versatile non-heme iron(II) alpha-ketoglutarate-dependent dioxygenase superfamily and catalyzes the oxygenolytic cleavage of a variety of different alkyl sulfate esters to the corresponding aldehyde and sulfate. The enzyme is only expressed under sulfur starvation conditions, providing a selective advantage for bacterial growth in soils and rhizosphere. Here we describe the crystal structure of AtsK in the apo form and in three complexes: with the cosubstrate alpha-ketoglutarate, with alpha-ketoglutarate and iron, and finally with alpha-ketoglutarate, iron, and an alkyl sulfate ester used as substrate in catalytic studies. The overall fold of the enzyme is closely related to that of the taurine/alpha-ketoglutarate dioxygenase TauD and is similar to the fold observed for other members of the enzyme superfamily. From comparison of these structures with the crystal structure of AtsK and its complexes, we propose a general mechanism for the catalytic cycle of the alpha-ketoglutarate-dependent dioxygenase superfamily.
authors.affiliation: Lehrstuhl für Strukturchemie, Universität Göttingen, Tammannstrasse 4, D-37077 Göttingen, Germany.
authors.forename: Ilka
authors.initials: I
authors.lastname: Müller
authors.forename: Antje
authors.initials: A
authors.lastname: Kahnert
authors.forename: Thomas
authors.initials: T
authors.lastname: Pape
authors.forename: George M
authors.initials: GM
authors.lastname: Sheldrick
authors.forename: Wolfram
authors.initials: W
authors.lastname: Meyer-Klaucke
authors.forename: Thomas
authors.initials: T
authors.lastname: Dierks
authors.forename: Michael
authors.initials: M
authors.lastname: Kertesz
authors.forename: Isabel
authors.initials: I
authors.lastname: Usón
mesh_terms: D020816:Amino Acid Motifs; D001051:Apoenzymes / Q000737:chemistry; D001426:Bacterial Proteins / Q000737:chemistry*; D001665:Binding Sites; D002264:Carboxylic Acids / Q000737:chemistry; D002384:Catalysis; D002413:Cations, Divalent / Q000737:chemistry; D002414:Cations, Monovalent / Q000737:chemistry; D018360:Crystallography, X-Ray; D019281:Dimerization; D005296:Ferrous Compounds / Q000737:chemistry*; D006801:Humans; D007656:Ketoglutaric Acids / Q000737:chemistry*; D006899:Mixed Function Oxygenases / Q000737:chemistry*; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D016958:Pseudomonas putida / Q000201:enzymology; D012492:Salts / Q000737:chemistry; D012964:Sodium / Q000737:chemistry; D013057:Spectrum Analysis; D040681:Structural Homology, Protein; D013379:Substrate Specificity; D013429:Sulfatases / Q000737:chemistry*; D014965:X-Rays
chemical_list: D001051:Apoenzymes; D001426:Bacterial Proteins; D002264:Carboxylic Acids; D002413:Cations, Divalent; D002414:Cations, Monovalent; D005296:Ferrous Compounds; D007656:Ketoglutaric Acids; D012492:Salts; D012964:Sodium; D006899:Mixed Function Oxygenases; D013429:Sulfatases; C019244:alkylsulfatase