Estimating amino acid substitution models and rooting bacterial trees subtitle

Reconstructing phylogenetic trees from protein sequences normally requires empirical amino acid substitution models to calculate the likelihood of trees or genetic distances between species. The tree of life is classified into three domains of Eukaryotes, Archaea, and Bacteria. The amino acid substitution models have been intensively studied for decades, but few are related to Bacteria. Rooting bacterial trees remains a challenging problem in the phylogenetic analysis due to the long branch separating Bacteria and other domains.