title: The origin of membrane bioenergetics.
abstract: Harnessing energy as ion gradients across membranes is as universal as the genetic code. We leverage new insights into anaerobe metabolism to propose geochemical origins that account for the ubiquity of chemiosmotic coupling, and Na(+)/H(+) transporters in particular. Natural proton gradients acting across thin FeS walls within alkaline hydrothermal vents could drive carbon assimilation, leading to the emergence of protocells within vent pores. Protocell membranes that were initially leaky would eventually become less permeable, forcing cells dependent on natural H(+) gradients to pump Na(+) ions. Our hypothesis accounts for the Na(+)/H(+) promiscuity of bioenergetic proteins, as well as the deep divergence between bacteria and archaea.
authors.affiliation: Research Department of Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK. nick.lane@ucl.ac.uk
authors.forename: Nick
authors.initials: N
authors.lastname: Lane
authors.forename: William F
authors.initials: WF
authors.lastname: Martin
mesh_terms: D001105:Archaea / Q000378:metabolism*; D019843:Archaeal Proteins / Q000737:chemistry / Q000378:metabolism; D001419:Bacteria / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism; D004734:Energy Metabolism; D060086:Hydrothermal Vents / Q000382:microbiology*; D016623:Ion Pumps / Q000737:chemistry / Q000378:metabolism*; D009995:Osmosis; D018892:Proton-Motive Force
chemical_list: D019843:Archaeal Proteins; D001426:Bacterial Proteins; D016623:Ion Pumps