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Updated: Aug 16, 2026

Structure and Coordination Determination of Peptide-metal Complexes Using 1D and 2D 1H NMR
Published on: December 16, 2013
Changes in E. coli inorganic pyrophosphatase structure induced by binding of metal activators
S M Avaeva1, E V Rodina, N N Vorobyeva
1Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119899, Russia. avaeva@protchem.genebee. msu.su
Abstract:
The three-dimensional structures of E. coli inorganic pyrophosphatase (PPase) and its complexes with Mn2+ in a high affinity site and with Mg2+ in high and low affinity sites determined by authors in 1994-1996 at 1.9-2.2 A resolution are compared. Metal ion binding initiates the shifts of alpha-carbon atoms and of functional groups and rearrangement of non-covalent interaction system of hexameric enzyme molecule. As a result, the apoPPase with six equal subunits turns after Mg2+ binding into the structure with three types of subunits distinguished by structure and occupance of the low affinity Mg2+ site. Induced asymmetry reflects the subunit interactions and cooperativity between Mg2+ binding sites. These molecular rearrangements are structural basis to account for special features of the enzyme behavior and to propose one of the pathways for enzymatic activity regulation of constitutive PPases in vivo.
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