1i74
From Proteopedia
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|PDB= 1i74 |SIZE=350|CAPTION= <scene name='initialview01'>1i74</scene>, resolution 2.2Å | |PDB= 1i74 |SIZE=350|CAPTION= <scene name='initialview01'>1i74</scene>, resolution 2.2Å | ||
|SITE= | |SITE= | ||
| - | |LIGAND= <scene name='pdbligand=MN:MANGANESE+(II)+ION'>MN</scene>, <scene name='pdbligand= | + | |LIGAND= <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=MN:MANGANESE+(II)+ION'>MN</scene>, <scene name='pdbligand=MSE:SELENOMETHIONINE'>MSE</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene> |
| - | |ACTIVITY= [http://en.wikipedia.org/wiki/Inorganic_diphosphatase Inorganic diphosphatase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.6.1.1 3.6.1.1] | + | |ACTIVITY= <span class='plainlinks'>[http://en.wikipedia.org/wiki/Inorganic_diphosphatase Inorganic diphosphatase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.6.1.1 3.6.1.1] </span> |
|GENE= | |GENE= | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY= | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1i74 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1i74 OCA], [http://www.ebi.ac.uk/pdbsum/1i74 PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1i74 RCSB]</span> | ||
}} | }} | ||
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[[Category: Merckel, M C.]] | [[Category: Merckel, M C.]] | ||
[[Category: Salminen, A.]] | [[Category: Salminen, A.]] | ||
| - | [[Category: MG]] | ||
| - | [[Category: MN]] | ||
| - | [[Category: SO4]] | ||
[[Category: hydrolase]] | [[Category: hydrolase]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 21:15:31 2008'' |
Revision as of 18:15, 30 March 2008
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| , resolution 2.2Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , , , | ||||||
| Activity: | Inorganic diphosphatase, with EC number 3.6.1.1 | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
STREPTOCOCCUS MUTANS INORGANIC PYROPHOSPHATASE
Overview
BACKGROUND: Streptococcus mutans pyrophosphatase (Sm-PPase) is a member of a relatively uncommon but widely dispersed sequence family (family II) of inorganic pyrophosphatases. A structure will answer two main questions: is it structurally similar to the family I PPases, and is the mechanism similar? RESULTS: The first family II PPase structure, that of homodimeric Sm-PPase complexed with metal and sulfate ions, has been solved by X-ray crystallography at 2.2 A resolution. The tertiary fold of Sm-PPase consists of a 189 residue alpha/beta N-terminal domain and a 114 residue mixed beta sheet C-terminal domain and bears no resemblance to family I PPase, even though the arrangement of active site ligands and the residues that bind them shows significant similarity. The preference for Mn2+ over Mg2+ in family II PPases is explained by the histidine ligands and bidentate carboxylate coordination. The active site is located at the domain interface. The C-terminal domain is hinged to the N-terminal domain and exists in both closed and open conformations. CONCLUSIONS: The active site similiarities, including a water coordinated to two metal ions, suggest that the family II PPase mechanism is "analogous" (not "homologous") to that of family I PPases. This is a remarkable example of convergent evolution. The large change in C-terminal conformation suggests that domain closure might be the mechanism by which Sm-PPase achieves specificity for pyrophosphate over other polyphosphates.
About this Structure
1I74 is a Single protein structure of sequence from Streptococcus mutans. Full crystallographic information is available from OCA.
Reference
Crystal structure of Streptococcus mutans pyrophosphatase: a new fold for an old mechanism., Merckel MC, Fabrichniy IP, Salminen A, Kalkkinen N, Baykov AA, Lahti R, Goldman A, Structure. 2001 Apr 4;9(4):289-97. PMID:11525166
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