1e9g
From Proteopedia
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STRUCTURE OF INORGANIC PYROPHOSPHATASE
Overview
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 ... [(full description)]
About this Structure
1E9G is a [Single protein] structure of sequence from [Saccharomyces cerevisiae] with MN and PO4 as [ligands]. Active as [Inorganic diphosphatase], with EC number [3.6.1.1]. Structure known Active Sites: ASA and ASB. Full crystallographic information is available from [OCA].
Reference
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
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