1e6a

Fluoride-inhibited substrate complex of Saccharomyces cerevisiae inorganic pyrophosphatase

spinqualitylabelsall models 1e6a, resolution 1.90Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1e6a is a 2 chain structure with sequence from Saccharomyces cerevisiae. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.9Å Ligands: F, MN, NA, PO4, POP Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function IPYR_YEAST Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed The wealth of kinetic and structural information makes inorganic pyrophosphatases (PPases) a good model system to study the details of enzymatic phosphoryl transfer. The enzyme accelerates metal-complexed phosphoryl transfer 10(10)-fold: but how? Our structures of the yeast PPase product complex at 1.15 A and fluoride-inhibited complex at 1.9 A visualize the active site in three different states: substrate-bound, immediate product bound, and relaxed product bound. These span the steps around chemical catalysis and provide strong evidence that a water molecule (O(nu)) directly attacks PPi with a pK(a) vastly lowered by coordination to two metal ions and D117. They also suggest that a low-barrier hydrogen bond (LBHB) forms between D117 and O(nu), in part because of steric crowding by W100 and N116. Direct visualization of the double bonds on the phosphates appears possible. The flexible side chains at the top of the active site absorb the motion involved in the reaction, which may help accelerate catalysis. Relaxation of the product allows a new nucleophile to be generated and creates symmetry in the elementary catalytic steps on the enzyme. We are thus moving closer to understanding phosphoryl transfer in PPases at the quantum mechanical level. Ultra-high resolution structures can thus tease out overlapping complexes and so are as relevant to discussion of enzyme mechanism as structures produced by time-resolved crystallography. Toward a quantum-mechanical description of metal-assisted phosphoryl transfer in pyrophosphatase.,Heikinheimo P, Tuominen V, Ahonen AK, Teplyakov A, Cooperman BS, Baykov AA, Lahti R, Goldman A Proc Natl Acad Sci U S A. 2001 Mar 13;98(6):3121-6. Epub 2001 Mar 6. PMID:11248042 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Inorganic pyrophosphatase 3D structures

Proteopedia Page Contributors and Editors (what is this?)

OCA