title: Two "unrelated" families of ATP-dependent enzymes share extensive structural similarities about their cofactor binding sites.
abstract: Two proteins, D-alanine:D-alanine ligase and cAMP-dependent protein kinase, share a remarkable degree of structural convergence despite having different three-dimensional folds and different enzymatic functions. Here we report that as many as 103 residues from 10 segments form two identical super-secondary structures between which the cofactor ATP is bound. The cofactor, two bound metal cations, and several water molecules form a large network of electrostatic and hydrophobic interactions common to both enzymes, and these are mediated by the similar placement of equivalent amino acids within the common supersecondary structures.
authors.affiliation: Department of Biochemistry, University of Turku, Finland.
authors.forename: K A
authors.initials: KA
authors.lastname: Denessiouk
authors.forename: J V
authors.initials: JV
authors.lastname: Lehtonen
authors.forename: T
authors.initials: T
authors.lastname: Korpela
authors.forename: M S
authors.initials: MS
authors.lastname: Johnson
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D000595:Amino Acid Sequence; D001665:Binding Sites; D003067:Coenzymes / Q000378:metabolism*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D010453:Peptide Synthases / Q000737:chemistry / Q000378:metabolism*; D017433:Protein Structure, Secondary
chemical_list: D003067:Coenzymes; D000255:Adenosine Triphosphate; D017868:Cyclic AMP-Dependent Protein Kinases; D010453:Peptide Synthases; C019638:D-alanylalanine synthetase