1OBW

STRUCTURE OF INORGANIC PYROPHOSPHATASE

Summary for 1OBW

• Entry DOI: 10.2210/pdb1obw/pdb
• Descriptor: INORGANIC PYROPHOSPHATASE, MAGNESIUM ION (3 entities in total)
• Functional Keywords: hydrolase, magnesium, metal binding
• Biological source: Escherichia coli
• Cellular location: Cytoplasm: P0A7A9
• Total number of polymer chains: 3
• Total formula weight: 58925.97

Authors

Oganessyan, V.Yu.,Harutyunyan, E.H.,Avaeva, S.M.,Oganessyan, N.N.,Mather, T.,Huber, R. (deposition date: 1996-10-09, release date: 1997-09-04, Last modification date: 2024-04-03)

Primary citation

Harutyunyan, E.H.,Oganessyan, V.Y.,Oganessyan, N.N.,Avaeva, S.M.,Nazarova, T.I.,Vorobyeva, N.N.,Kurilova, S.A.,Huber, R.,Mather, T.
Crystal structure of holo inorganic pyrophosphatase from Escherichia coli at 1.9 A resolution. Mechanism of hydrolysis.
Biochemistry, 36:7754-7760, 1997

PubMed Abstract: Crystalline holo inorganic pyrophosphatase from Escherichia coli was grown in the presence of 250 mM MgCl2. The crystal structure has been solved by Patterson search techniques and refined to an R-factor of 17.6% at 1.9 A resolution. The upper estimate of the root-mean-square error in atomic positions is 0.26 A. These crystals belong to space group P3(2)21 with unit cell dimensions a = b = 110.27 A and c = 78.17 A. The asymmetric unit contains a trimer of subunits, i.e., half of the hexameric molecule. In the central cavity of the enzyme molecule, three Mg2+ ions, each shared by two subunits of the hexamer, are found. In the active sites of two crystallographically independent subunits, two Mg2+ ions are bound. The second active site Mg2+ ion is missing in the third subunit. A mechanism of catalysis is proposed whereby a water molecule activated by a Mg2+ ion and Tyr 55 play essential roles.

PubMed: 9201917
DOI: 10.1021/bi962637u

Experimental method

X-RAY DIFFRACTION (1.9 Å)