Horizontal transfer of bacterial polyphosphate kinases to eukaryotes: implications for the ice age and land colonisation

Abstract

Evidence for the possible origins of these eukaryote PPK1s and PPK2s and potential prokaryote donors via horizontal gene transfer is presented. The selective advantage of acquiring and maintaining a prokaryote PPK in a eukaryote is proposed to enhance stress tolerance in a changing environment related to the capture and metabolism of inorganic phosphate compounds. Bacterial PPKs may also have enhanced the abilities of marine phytoplankton to sequester phosphate, hence accelerating global carbon fixation.