1qez

SULFOLOBUS ACIDOCALDARIUS INORGANIC PYROPHOSPHATASE: AN ARCHAEL PYROPHOSPHATASE.

spinqualitylabelsall models 1qez, resolution 2.70Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1qez is a 6 chain structure with sequence from Sulfolobus acidocaldarius. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.7Å Ligands: MG Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function IPYR_SULAC 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 first crystal structure of an inorganic pyrophosphatase (S-PPase) from an archaebacterium, the thermophile Sulfolobus acidocaldarius, has been solved by molecular replacement and refined to an R-factor of 19.7% at 2.7 A. S-PPase is a D3 homohexameric protein with one Mg2+ per active site in a position similar to, but not identical with, the first activating metal in mesophilic pyrophosphatases (PPase). In mesophilic PPases, Asp65, Asp70, and Asp102 coordinate the Mg2+, while only Asp65 and Asp102 do in S-PPase, and the Mg2+ moves by 0.7 A. S-PPase may therefore be deactivated at low temperature by mispositioning a key metal ion. The monomer S-PPase structure is very similar to that of Thermus thermophilus (T-PPase) and Escherichia coli (E-PPase), root-mean-square deviations around 1 A/Calpha. But the hexamer structures of S- and T-PPase are more tightly packed and more similar to each other than they are to that of E-PPase, as shown by the increase in surface area buried upon oligomerization. In T-PPase, Arg116 creates an interlocking ionic network to both twofold and threefold related monomers; S-PPase has hydrophilic interactions to threefold related monomers absent in both E- and T-PPase. In addition, the thermostable PPases have about 7% more hydrogen bonds per monomer than E-PPase, and, especially in S-PPase, additional ionic interactions anchor the C-terminus to the rest of the protein. Thermostability in PPases is thus due to subtle improvements in both monomer and oligomer interactions. Sulfolobus acidocaldarius inorganic pyrophosphatase: structure, thermostability, and effect of metal ion in an archael pyrophosphatase.,Leppanen VM, Nummelin H, Hansen T, Lahti R, Schafer G, Goldman A Protein Sci. 1999 Jun;8(6):1218-31. PMID:10386872 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Inorganic pyrophosphatase 3D structures

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