Joined: May 2002
Free online article comparing PPases and F1F0-ATPases:
FEBS Lett 1999 Sep 3;457(3):527-33
H(+)-PPases: a tightly membrane-bound family
Baltscheffsky M, Schultz A, Baltscheffsky H.
Department of Biochemistry, Arrhenius Laboratories, Stockholm University, S-106 91, Stockholm, Sweden.
The earliest known H(+)-PPase (proton-pumping inorganic pyrophosphatase), the integrally membrane-bound H(+)-PPi synthase (proton-pumping 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(+)-PPase genes has led to the recognition that the corresponding proteins form a family of extremely similar proton-pumping enzymes. The bacterial H(+)-PPi synthase and two algal vacuolar H(+)-PPases are homologous with this family, as deduced from their cloned genes. The prokaryotic and algal homologues differ more than the H(+)-PPases from higher plants, facilitating recognition of functionally significant entities. Primary structures of H(+)-PPases are reviewed and compared with H(+)-ATPases and soluble PPases.