Sandbox Reserved 494: Difference between revisions
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==Reaction analysis of the catalytic sites== | ==Reaction analysis of the catalytic sites== | ||
The energy for ATP synthesis is provided from proton transport along the gradient of electrochemical potential of protons across membranes (△H). When the magnitude of △H is large, as in functionalmitochondrial, downhill proton flow through F<sub>0</sub> causes rotation of the F<sub>0</sub> rotor and hence rotation of the γε-subunits of F<sub>1</sub>. The rotary motion of the γ alternates the structure of the β-subunit so the ATP is synthesized<ref>PMID: 12788493</ref>. | The energy for ATP synthesis is provided from proton transport along the gradient of electrochemical potential of protons across membranes (△H). When the magnitude of △H is large, as in functionalmitochondrial, downhill proton flow through F<sub>0</sub> causes rotation of the F<sub>0</sub> rotor and hence rotation of the γε-subunits of F<sub>1</sub>. The rotary motion of the γ alternates the structure of the β-subunit so the ATP is synthesized<ref>PMID: 12788493</ref>. | ||
Mutagenesis of catalyticsites of ATP synthase have proceeded extensively in the ''E. coli'' enzymes, somewhat less so in ''Saccharomyces cerevisiae'' and ''Bacillus'' PS3, and to far lesser extent in other species. Almost without exception, detailed in vitro biochemical analyses of purified mutant enzymes have been limited to the ATP hydrolysis reaction. However, in both yeast and E. coli, growth tests on nonfermentable substrates provide sensitive if quantative assays of ATP synthesis in the cell. Ligands to the Mg<sup>2+</sup> cation have been studied in detail by mutagenesis and functional analysis <ref>PMID: 9425083 </ref> . | Mutagenesis of catalyticsites of ATP synthase have proceeded extensively in the ''E. coli'' enzymes, somewhat less so in ''Saccharomyces cerevisiae'' and ''Bacillus'' PS3, and to far lesser extent in other species. Almost without exception, detailed in vitro biochemical analyses of purified mutant enzymes have been limited to the ATP hydrolysis reaction. However, in both yeast and E. coli, growth tests on nonfermentable substrates provide sensitive if quantative assays of ATP synthesis in the cell. Ligands to the Mg<sup>2+</sup> cation have been studied in detail by mutagenesis and functional analysis <ref>PMID: 9425083 </ref>. | ||
[[Image:1c17_ligand.jpg | thumb|frame|Octahedral coordination of Mg<sup>2+</sup> in the catalytic site of ATP synthase.]] | |||
==Perspective== | ==Perspective== | ||
