title: Crystallization of a complex of Caenorhabditis elegans diadenosine tetraphosphate hydrolase and a non-hydrolysable substrate analogue, AppCH2ppA.
abstract: The molecule diadenosine tetraphosphate (Ap(4)A) has been suggested to be a component of the cellular response to metabolic stress and/or, via the intracellular Ap(3)A/Ap(4)A ratio, to be involved in differentiation and apoptosis. Thus, the enzyme Ap(4)A hydrolase has a key metabolic role through regulation of the intracellular Ap(4)A levels. Crystals of this enzyme from the nematode Caenorhabditis elegans have been obtained in the presence of a non-hydrolysable substrate analogue, AppCH(2)ppA. The crystals belong to space group P2(1), unit-cell parameters a = 57.6, b = 36.8, c = 68.9 A, beta = 114.2 degrees, and diffract to approximately 2.0 A. Determination of the structure of this complex will provide insights into the substrate specificity and catalytic activity of this class of enzymes.
authors.affiliation: Krebs Institute for Biomolecular Research, Department of Molecular Biology and Biotechnology, University of Sheffield, Western Bank, Sheffield S10 2TN, England.
authors.forename: Scott
authors.initials: S
authors.lastname: Bailey
authors.forename: Svetlana E
authors.initials: SE
authors.lastname: Sedelnikova
authors.forename: G Michael
authors.initials: GM
authors.lastname: Blackburn
authors.forename: Hend M
authors.initials: HM
authors.lastname: Abdelghany
authors.forename: Alexander G
authors.initials: AG
authors.lastname: McLennan
authors.forename: John B
authors.initials: JB
authors.lastname: Rafferty
mesh_terms: D017766:Acid Anhydride Hydrolases / Q000737:chemistry* / Q000378:metabolism; D000818:Animals; D017173:Caenorhabditis elegans / Q000737:chemistry / Q000201:enzymology*; D003460:Crystallization; D018360:Crystallography, X-Ray; D015226:Dinucleoside Phosphates / Q000737:chemistry* / Q000378:metabolism; D011487:Protein Conformation; D013379:Substrate Specificity
chemical_list: D015226:Dinucleoside Phosphates; C020733:diadenosine tetraphosphate; D017766:Acid Anhydride Hydrolases; C020023:bis(5'-nucleosyl)tetraphosphatase (asymmetrical)