title: Structural and mechanistic comparisons of the metal-binding members of the vicinal oxygen chelate (VOC) superfamily.
abstract: The vicinal oxygen chelate family of enzymes catalyzes a highly diverse set of chemistries that derives from one common mechanistic trait: bidentate coordination to a divalent metal center by a substrate or intermediate or transition state through vicinal oxygen atoms. The array of reactions catalyzed by this family is mediated structurally by a common fold and protein-chelating residues that secure and localize a metal ion. The common fold has topological symmetry being comprised of two βαβββ units that form an incompletely closed barrel of β-sheet about the metal ion. Interestingly, despite the diversity of the reactions catalyzed and the large number of metals observed to bind and promote the chemistry, this semi-symmetrical open barrel extends metal liganding side chains inward from a highly positionally conserved constellation of amino acid residues within the structure. Moreover, the core barrel fold arises from an array of possible intra/inter domain and subunit arrangements of the individual βαβββ units that are universally observed to stack side-by-side contacting along the first β-strand of each. While there are examples of enzymes that use this fold and do not bind a metal ion, this review is concerned with summarizing the key structural and mechanistic correlations that can be made for the metal-dependent vicinal oxygen chelate enzyme family members.
authors.affiliation: Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, 3210 N. Cramer St, Milwaukee, WI 53211-3029, United States
authors.forename: Panqing
authors.initials: P
authors.lastname: He
authors.forename: Graham R
authors.initials: GR
authors.lastname: Moran
mesh_terms: D049308:Dioxygenases / Q000737:chemistry / Q000378:metabolism; D008670:Metals / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D010105:Oxygenases / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D011506:Proteins / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D008670:Metals; D011506:Proteins; D010105:Oxygenases; D049308:Dioxygenases; D010100:Oxygen