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  Topic: ATPase origins, Stuff pertinent to this question< Next Oldest | Next Newest >  

Posts: 319
Joined: May 2002

(Permalink) Posted: Oct. 01 2002,13:47   

This thread is for references to lit. on, or relevant to, the origins of F1F0 ATPase.  I just came across some and I know of some others, I will post them whenever I dig 'em up.


Subunit rotation of ATP synthase embedded in membranes: a or subunit rotation relative to the c subunit ring

Kazuaki Nishio *, Atsuko Iwamoto-Kihara *, Akitsugu Yamamoto , Yoh Wada *, and Masamitsu Futai *
*Division of Biological Sciences, Institute of Scientific and Industrial Research, Osaka University, Core Research for Evolutional Science and Technology (CREST) of the Japan Science and Technology Corporation, Osaka 567-0047, Japan; and Department of Physiology, Kansai Medical University, Moriguchi, Osaka 570-8506, Japan

Edited by Paul D. Boyer, University of California, Los Angeles, CA, and approved August 15, 2002 (received for review March 13, 2002)

ATP synthase FoF1 (33ab2c10-14) couples an electrochemical proton gradient and a chemical reaction through the rotation of its subunit assembly. In this study, we engineered FoF1 to examine the rotation of the catalytic F1 or membrane sector Fo a subunit when the Fo c subunit ring was immobilized; a biotin-tag was introduced onto the or a subunit, and a His-tag onto the c subunit ring. Membrane fragments were obtained from Escherichia coli cells carrying the recombinant plasmid for the engineered FoF1 and were immobilized on a glass surface. An actin filament connected to the or a subunit rotated counterclockwise on the addition of ATP, and generated essentially the same torque as one connected to the c ring of FoF1 immobilized through a His-tag linked to the  or subunit. These results established that the c10-14 and 33ab2 complexes are mechanical units of the membrane-embedded enzyme involved in rotational catalysis.

Some have argued that the ATPase may be descended from a pyrophophatase, so this is relevant:


Proc. Natl. Acad. Sci. USA, 10.1073/pnas.212410399

Pyrophosphate-producing protein dephosphorylation by HPr kinase/phosphorylase: A relic of early life?

In most Gram-positive bacteria, serine-46-phosphorylated HPr (P-Ser-HPr) controls the expression of numerous catabolic genes (10% of their genome) by acting as catabolite corepressor. HPr kinase/phosphorylase (HprK/P), the bifunctional sensor enzyme for catabolite repression, phosphorylates HPr, a phosphocarrier protein of the sugar-transporting phosphoenolpyruvate/glycose phosphotransferase system, in the presence of ATP and fructose-1,6-bisphosphate but dephosphorylates P-Ser-HPr when phosphate prevails over ATP and fructose-1,6-bisphosphate. We demonstrate here that P-Ser-HPr dephosphorylation leads to the formation of HPr and pyrophosphate. HprK/P, which binds phosphate at the same site as the phosphate of ATP, probably uses the inorganic phosphate to carry out a nucleophilic attack on the phosphoryl bond in P-Ser-HPr. HprK/P is the first enzyme known to catalyze P-protein dephosphorylation via this phospho-phosphorolysis mechanism. This reaction is reversible, and at elevated pyrophosphate concentrations, HprK/P can use pyrophosphate to phosphorylate HPr. Growth of Bacillus subtilis on glucose increased intracellular pyrophosphate to concentrations (6 mM), which in in vitro tests allowed efficient pyrophosphate-dependent HPr phosphorylation. To effectively dephosphorylate P-Ser-HPr when glucose is exhausted, the pyrophosphate concentration in the cells is lowered to 1 mM. In B. subtilis, this might be achieved by YvoE. This protein exhibits pyrophosphatase activity, and its gene is organized in an operon with hprK.

  5 replies since Oct. 01 2002,13:47 < Next Oldest | Next Newest >  


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