Analysis of the Staphylococcus aureus DgkB structure reveals a common catalytic mechanism for the soluble diacylglycerol kinases.
Soluble diacylglycerol (DAG) kinases function as regulators of diacylglycerol metabolism in cell signaling and intermediary metabolism. We report the structure of a DAG kinase, DgkB from Staphylococcus aureus, both as the free enzyme and in complex with ADP. The molecule is a tight homodimer, and each monomer comprises two domains with the catalytic center located within the interdomain cleft. Two distinctive features of DkgB are a structural Mg2+ site and an associated Asp*water*Mg2+ network that extends toward the active site locale. Site-directed mutagenesis revealed that these features play important roles in the catalytic mechanism. The key active site residues and the components of the Asp*water*Mg2+ network are conserved in the catalytic cores of the mammalian signaling DAG kinases, indicating that these enzymes use the same mechanism and have similar structures as DgkB.
Miller
Darcie J
DJ
Department of Structural Biology, St. Jude Children's Research Hospital, and Department of Molecular Sciences, University of Tennessee Health Science Center, 332 North Lauderdale Street, Memphis, TN 38105, USA.
Jerga
Agoston
A
Rock
Charles O
CO
White
Stephen W
SW
D000244:Adenosine Diphosphate / Q000737:chemistry; D000595:Amino Acid Sequence; D001224:Aspartic Acid / Q000737:chemistry; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics; D001665:Binding Sites; D002384:Catalysis; D002413:Cations, Divalent / Q000737:chemistry; D019852:Diacylglycerol Kinase / Q000737:chemistry* / Q000235:genetics; D019281:Dimerization; D006801:Humans; D008274:Magnesium / Q000737:chemistry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D017386:Sequence Homology, Amino Acid; D012995:Solubility; D013211:Staphylococcus aureus / Q000201:enzymology*
D001426:Bacterial Proteins; D002413:Cations, Divalent; D001224:Aspartic Acid; D000244:Adenosine Diphosphate; D019852:Diacylglycerol Kinase; D008274:Magnesium