Links between hydrothermal environments, pyrophosphate, Na+, and early evolution
2011 (English)In: Origins of life and evolution of the biosphere, ISSN 0169-6149, E-ISSN 1573-0875, Vol. 41, no 5, 483-493 p.Article in journal (Refereed) Published
The discovery that photosynthetic bacterial membrane-bound inorganic pyrophosphatase (PPase) catalyzed light-induced phosphorylation of orthophosphate (Pi) to pyrophosphate (PPi) and the capability of PPi to drive energy requiring dark reactions supported PPi as a possible early alternative to ATP. Like the proton-pumping ATPase, the corresponding membrane-bound PPase also is a H+-pump, and like the Na+-pumping ATPase, it can be a Na+-pump, both in archaeal and bacterial membranes. We suggest that PPi and Na+ transport preceded ATP and H+ transport in association with geochemistry of the Earth at the time of the origin and early evolution of life. Life may have started in connection with early plate tectonic processes coupled to alkaline hydrothermal activity. A hydrothermal environment in which Na+ is abundant exists in sediment-starved subduction zones, like the Mariana forearc in the W Pacific Ocean. It is considered to mimic the Archean Earth. The forearc pore fluids have a pH up to 12.6, a Na+-concentration of 0.7 mol/kg seawater. PPi could have been formed during early subduction of oceanic lithosphere by dehydration of protonated orthophosphates. A key to PPi formation in these geological environments is a low local activity of water.
Place, publisher, year, edition, pages
2011. Vol. 41, no 5, 483-493 p.
brucite, early evolution, hydrothermal systems, Mariana forearc, membrane-bound inorganic pyrophosphatase, proton pump, pyrophosphate, serpentinization, sodium pump, subduction zones
Geochemistry Biochemistry and Molecular Biology
IdentifiersURN: urn:nbn:se:su:diva-62946DOI: 10.1007/s11084-011-9235-4ISI: 000300367500007OAI: oai:DiVA.org:su-62946DiVA: diva2:446000