The ATPases of Propionigenium modestum and Bacillus alcalophilus. Strategies for ATP synthesis under low energy conditions.
In Propionigenium modestum, ATP synthesis is coupled via delta mu Na+ to the decarboxylation of (S)-methylmalonyl-CoA. The low energy yield of this reaction implies that approx. 4 decarboxylation cycles are necessary to synthesize 1 molecule of ATP. Theoretical considerations in accord with experimental results suggest ATP synthesis in P. modestum at delta mu Na+ = -110 mV. Other anaerobic bacteria synthesize ATP at a delta mu H+ of similar size and alkaliphilic bacteria at pH 10.3 have a delta mu H+ of only -103 mV. In these cases, the H+(Na+) to ATP stoichiometry must be at least 4.
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Mikrobiologisches Institut, Eidgenössische Technische Hochschule, ETH-Zentrum, Zürich, Switzerland.
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000096:biosynthesis*; D001407:Bacillus / Q000201:enzymology*; D004734:Energy Metabolism; D006089:Gram-Negative Anaerobic Bacteria / Q000201:enzymology*
D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases