The A1Ao ATP synthase from archaea represents a class of chimeric ATPases/synthases, whose function and general structural design share characteristics both with vacuolar V1Vo ATPases and with F1Fo ATP synthases. http://www.ncbi.nlm.nih.gov/pubmed/16563431 A1A0 ATP synthase catalyzes the formation of the energy currency ATP by a membrane-embedded electrically-driven motor. The archaeon in this study, Pyrococcus horikoshii OT3 is an extreemophile residing in oceanic deep sea vents. ( )The membrane-embedded electrically-driven motor (A0) is very different in archaea with sometimes novel, exceptional subunit composition and coupling stoichiometries that may reflect the differences in energy-conserving mechanisms as well as adaptation to temperatures at or above 100 degrees C.
http://www.mendeley.com/research/bioenergetics-archaea-atp-synthesis-under-harsh-environmental-conditions/
Because some archaea are rooted close to the origin in the tree of life, these unusual mechanisms are considered to have developed very early in the history of life and, therefore, may represent first energy-conserving mechanisms.
http://www.mendeley.com/research/bioenergetics-archaea-atp-synthesis-under-harsh-environmental-conditions/