2btd

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spinqualitylabelsall models 2btd, resolution 2.60Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

CRYSTAL STRUCTURE OF DHAL FROM E. COLI

Overview

Dihydroxyacetone (Dha) kinases are a family of sequence-related enzymes, that utilize either ATP or phosphoenolpyruvate (PEP) as source of high, energy phosphate. The PEP-dependent Dha kinase of Escherichia coli, consists of three subunits. DhaK and DhaL are homologous to the Dha and, nucleotide-binding domains of the ATP-dependent kinase of Citrobacter, freundii. The DhaM subunit is a multiphosphorylprotein of the PEP:sugar, phosphotransferase system (PTS). DhaL contains a tightly bound ADP as, coenzyme that gets transiently phosphorylated in the double displacement, of phosphate between DhaM and Dha. Here we report the 2.6A crystal, structure of the E.coli DhaL subunit. DhaL folds into an eight-helix, barrel of regular up-down topology with a hydrophobic core made up of, eight interlocked aromatic residues and a molecule of ADP bound at the, narrower end of the barrel. The alpha and beta phosphates of ADP are, complexed by two Mg2+ and by a hydrogen bond to the imidazole ring of an, invariant histidine. The Mg ions in turn are coordinated by three, gamma-carboxyl groups of invariant aspartate residues. Water molecules, complete the octahedral coordination sphere. The nucleotide is capped by, an alpha-helical segment connecting helices 7 and 8 of the barrel. DhaL, and the nucleotide-binding domain of the C.freundii kinase assume the same, fold but display strongly different surface potentials. The latter, observation and biochemical data indicate that the domains of the, C.freundii Dha kinase constitute one cooperative unit and are not randomly, interacting and independent like the subunits of the E.coli enzyme.

About this Structure

2BTD is a Single protein structure of sequence from Escherichia coli with MG and ADP as ligands. Known structural/functional Site: . Full crystallographic information is available from OCA.

Reference

Crystal structure of the nucleotide-binding subunit DhaL of the Escherichia coli dihydroxyacetone kinase., Oberholzer AE, Schneider P, Baumann U, Erni B, J Mol Biol. 2006 Jun 9;359(3):539-45. Epub 2006 Apr 18. PMID:16647083

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