ATP synthase evolution on a cross-braced dated tree of life

Area of Science:

• Molecular Evolution
• Cellular Biology
• Phylogenetics

Background:

• The evolutionary timeline of early cellular life, particularly the emergence of eukaryotes, remains uncertain.
• ATP synthase, a crucial enzyme complex, is hypothesized to predate the Last Universal Common Ancestor (LUCA).
• Phylogenetic analyses of ATP synthase and ribosomal genes are vital for reconstructing the tree of life.

Purpose of the Study:

• To reconstruct and date the evolutionary history of ATP synthases.
• To establish an absolute timeline for early cellular evolution and key events like eukaryogenesis.
• To refine the phylogenetic tree of life using an expanded dataset and novel methods.

Main Methods:

• Reconstruction of ATP synthase evolutionary history using an expanded taxon sampling.
• Development of a phylogenetic cross-bracing approach to constrain speciation node timings.
• Integration of phylogenetic data with evidence from endosymbioses and ancient gene duplications.

Main Results:

• A highly resolved and dated species tree for ATP synthase evolution.
• The divergence of ATP synthase into F- and A/V-type lineages occurred over 4 billion years ago, potentially before Archaea and Bacteria diversified.
• The eukaryotic nuclear and mitochondrial lineages diverged from their archaeal and bacterial relatives around the same time (2.1-2.7 billion years ago).

Conclusions:

• The divergence of ATP synthase is an ancient event in cellular evolution.
• This study provides a robust, dated timeline for early life evolution and eukaryogenesis.
• The findings offer new insights into the timing of major evolutionary transitions in the history of life.