Evolution of the Vacuolar H + -ATPase: Implications for the Origin of Eukaryotes

摘要: Abstract Active transport across the vacuolar components of eukaryotic endomembrane system is energized by a specific H+-ATPase. The amino acid sequences 70- and 60-kDa subunits H+-ATPase are approximately equal to 25% identical beta alpha subunits, respectively, eubacterial-type F0F1-ATPases. We now report that same 50% sulfur-metabolizing Sulfolobus acidocaldarius, an archaebacterium (Archaeobacterium). Moreover, homologue 88-amino stretch near amino-terminal end 70-kDa subunit absent from F0F1-ATPase but present in Sulfolobus. Since two types (alpha subunits; 60- subunits) homologous each other, they must have arisen gene duplication occurred prior last common ancestor eubacteria, eukaryotes, Thus, phylogenetic tree can be rooted at site where occurred. inferred evolutionary contains main branches: eubacterial branch eocyte gave rise host cell. implication eukaryotes arose internalization plasma membrane archaebacterial-like ancestral