H.-proton-pumping inorganic pyrophosphatase: a tightly membrane-bound family 

 -  FEBS Letters, 452(3), p.121-127, 1999 .
<br/><br/> The earliest known H+-proton-pumping inorganic pyrophosphatase, the integrally membrane-bound H+-protonpumping inorganic pyrophosphate synthase from Rhodospirillum rubrum, is still the only alternative to H+-ATP synthase in biological electron transport phosphorylation. Cloning of several higher plant vacuolar H+-proton-pumping inorganic pyrophosphatase genes has led to the recognition that the corresponding proteins form a family of extremely similar proton-pumping enzymes. The bacterial H+-proton-pumping inorganic pyrophosphate synthase and two algal vacuolar H+-proton-pumping inorganic pyrophosphatases are homologous with this family, as deduced from their cloned genes. The prokaryotic and algal homologues differ more than the H+-proton-pumping inorganic pyrophosphatases from higher plants, facilitating recognition of functionally significant entities. Primary structures of H+- proton-pumping inorganic pyrophosphatases are reviewed and compared with H+-ATPases and soluble proton-pumping inorganic pyrophosphatases. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>H.-PROTON-PUMPING INORGANIC PYROPHOSPHATASE<br/>H.-PROTON-PUMPING INORGANIC PYROPHOSPHATE SYNTHASE<br/>H.-ATPASE<br/>H.-ATP SYNTHASE<br/>AMINO ACID SEQUENCE<br/>EVOLUTION<br/>ENZYME FAMILY