1i74: Difference between revisions
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[[Image:1i74.gif|left|200px]] | [[Image:1i74.gif|left|200px]] | ||
'''STREPTOCOCCUS MUTANS INORGANIC PYROPHOSPHATASE''' | {{Structure | ||
|PDB= 1i74 |SIZE=350|CAPTION= <scene name='initialview01'>1i74</scene>, resolution 2.2Å | |||
|SITE= | |||
|LIGAND= <scene name='pdbligand=MN:MANGANESE+(II)+ION'>MN</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene> and <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] | |||
|GENE= | |||
}} | |||
'''STREPTOCOCCUS MUTANS INORGANIC PYROPHOSPHATASE''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
1I74 is a [ | 1I74 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Streptococcus_mutans Streptococcus mutans]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1I74 OCA]. | ||
==Reference== | ==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:[http:// | 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:[http://www.ncbi.nlm.nih.gov/pubmed/11525166 11525166] | ||
[[Category: Inorganic diphosphatase]] | [[Category: Inorganic diphosphatase]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
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[[Category: hydrolase]] | [[Category: hydrolase]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 11:46:21 2008'' | ||
Revision as of 09:46, 20 March 2008
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| 1i74, resolution 2.2Å | |||||||||||||
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| Ligands: | MN, MG and SO4 | ||||||||||||
| Activity: | Inorganic diphosphatase, with EC number 3.6.1.1 | ||||||||||||
| 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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