Sandbox Reserved 320: Difference between revisions
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{{ | {{STRUCTURE_1faj| PDB=1faj | SCENE=}} | ||
<scene name='Sandbox_Reserved_320/Ppase/1'>Soluble inorganic pyrophosphatase</scene> is a ubiquitous enzyme that plays an important role in energy metabolism <ref name= "kankare"> PMID: 7971944</ref>. Energy metabolism is made possible by soluble inorganic pyrophosphatases (PPases) by their hydrolyzing inorganic phosphates into two molecules of orthophosphate <ref name = "samygina"> PMID: 11846572</ref>. PPases may have had an important role in evolution by aiding in accurate DNA copying during chromosome duplication <ref name = "kankare"/>. Escherichia coli (E-coli bacteria) and Saccharomyces cerevisiae (S. cerevisiae yeast) PPases, E-PPase and Y-PPase respectively, are the two best studied PPases <ref name = "kankare"/>. | |||
== '''Inorganic Pyrophosphatase''' == | == '''Inorganic Pyrophosphatase''' == | ||
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==Structure== | |||
E-PPase, a homohexameric protein <ref name = "wong"> PMID: 5498422 </ref>, contains 175 amino-acid residues in each subunit <ref name = "lahti"> PMID: 2848015 </ref>. The protein's topology is described as a five stranded β-barrel that is distorted, highly twisted, and composted of strands β1, β4, β5, β6 and β7, capped on top with α-helix B and the bottom by a loop between strand five and strand six <ref name = "kankare"/>. The active site exists in the bowl formed by the <scene name='Sandbox_Reserved_320/Excursions/1'>excursions</scene> <ref name = "kankare"/>. | |||
==Function== | |||
[[Image:Figure_1.png|left|thumb|'''Figure 1.''' Reaction catalyzed by Inorganic Pyrophosphatase (PPase)]]PPases act to cleave PPi as it is a byproduct in many biosynthetic reactions that include protein, RNA and DNA synthesis<ref name = "kankare"/>. By cleaving the PPi in these synthesis reactions it shifts the equilibrium constants towards biosynthesis <ref name ="kankare"/>. In order to achieve PPi cleavage PPases require a divalent metal ion, usually magnesium <ref name = "kankare"/>. Calcium, alternatively, has been shown to fully suppress PPase activity <ref name = "samygina"/>. PPi hydrolysis is a complicated process that is still not fully understood <ref name = "samygina"/>. | |||
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==References== | |||
<references/> | |||