An ATPase From Halobacterium Saccharovorum
Report describes purification and determination of subunit structure of membrane-bound adenosinetriphosphatase (ATPase) from archaebacterium Halobacterium saccharovorum.
Hochstein, L. I.↗
Engineering topics
Altekar, W.
Publications and source records attributed to Altekar, W..
Is the ATPase from halobacterium saccharovorum an evolutionary relic?
The ATP Synthase Complex present in the membranes of mitochondria, chloroplasts or bacteria is composed of 2 sectors: FO, an integral membrane protein consisting of 3 subunits mediating proton translocation across the membrane and F1, the catalytic component composed of 5 non-identical subunits. The apparent early origin of the ATP Synthase Complex, as implied by its ubiquitous distribution, seems inconsistent with its structural and functional complexity and raises the question if simpler versions of the ATP Synthase exist. Such an ATP Synthase has been searched for in various Archaebacteria. A purified halobacterial ATPase activity which possesses certain properties consistent with those of an ATP Synthase but which has a different subunit structure is described.
Hochstein, L. I.↗
On archaebacterial ATPase from Halobacterium saccharovorum
The energy transducing ATPase from Halobacterium saccharovorum was studied in order to define the origin of energy transducing systems. The ATPase required high salt concentration (4M NaCl) for activity; activity was rapidly lost when NaCl was below 1 Molar. At low salt concentration, the membrane bound ATPase activity could be stabilized in presence of spermine. However, following solubilization spermine was ineffective. Furthermore, F1 ATPase activity was stabilized by ammonium sulfate even when the NaCl concentration was less than 1 Molar. These studies suggest that stabilization by hydrophobic interactions preceded ionic ones in the evolution of the energy transducing ATPases.
Kristjansson, H.↗