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“This last issue of OLEB of 2011 contains a collection of papers from ORIGINS 2011. The conference, which was jointly organized by Bioastronomy (IAU Commission 51) and ISSOL, was held in Montpellier, France from 3 to 8 July, 2011. find more The joint meeting was an experiment for both organizations and was universally considered to have been a great success. It has been decided to repeat the exercise and the next conference will be held in 2014 in Nara, Japan. OLEB congratulates the two societies and, particularly, the Local Organizing Committee of ORIGINS 2011, which was chaired by Muriel Gargaud and Robert Pascal. ORIGINS 2011 photo by Innovaxiom (Paris). Open Access This article is distributed under the

terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.”
“Introduction Lipmann (1965) assumed that, on the phosphate side, ‘the group potential might have originated with inorganic pyrophosphate (PPi) as the primitive group carrier’. The discovery that photosynthetic bacterial membrane-bound inorganic pyrophosphatase (PPase) catalyzed light-induced Galactosylceramidase phosphorylation of orthophosphate (Pi) to pyrophosphate (Baltscheffsky et al. 1966) and the capability of PPi to drive energy requiring dark reactions (Baltscheffsky

1967) supported pyrophosphate as a possible early alternative to adenosine triphosphate (ATP), the main chemical energy currency in living cells. Like the adenosine triphosphatase (ATPase), the corresponding membrane-bound PPase is also a H+-pump (Moyle et al. 1974), and can be a Na+-pump in both archaeal and bacterial membranes (Malinen et al. 2007). Support has been obtained for an earlier transport of Na+ than of H+ through biomembranes (Mulkidjanian et al. 2008a). The hyperthermophilic bacterium Thermotoga maritima, found in hydrothermal environments, as well as the mesophilic Methanosarcina mazei contain membrane-bound PPases (Tm-PPase and Mm-PPase, respectively) that are homologous to H+-PPases (Belogurov et al. 2005; Malinen et al. 2008). Both Tm-PPase and Mm-PPase have an absolute requirement for Na+, but display maximal activity in the presence of millimolar levels of K+.