Insertions in protein sequences for Taxonomy and Phylogeny in Pseudomonadaceae and Moraxellaceae families (Pseudomonadales Order)

Abstract

Pseudomonadaceae y Moraxellaceae families comprise species with medical, agricultural and biotechnological relevance.  Pseudomonas aeruginosa and Acinetobacter baumanii, for example, are opportunist pathogens responsible for several nosocomial infections. The Pseudomonadaceae family also includes the phytopathogenic bacteria Pseudomonas syringae and the denitrifying species Azotobacter vinelandii, both with agriculture impact. Even though Pseudomonadaceae and Moraxellaceae have been widely studied, few studies have been conducted to the identification of molecular markers that could be used to distinguish members of these families from other groups of bacteria. The identification of Indels (insertions or deletions) in conserved proteins sequences has been widely used for taxonomic and evolutionary studies in bacteria. In the present study, we investigated whether insertions identified in highly conserved proteins may be used as molecular markers for taxonomic and phylogenetic studies in Pseudomonadaceae and Moraxellaceae families. For this purpose, DNA repair and replication-related protein sequences were obtained from the international databases and aligned using ClustalX2. The one amino acid length insertion identified in the protein DNA polymerase I distinguishes the Pseudomonadaceae y Ventosimonadaceae families; and the larger 11 amino acids insertion, also identified in this protein, supports the monophyletic grouping of Psychrobacter and Moraxella genera. Moreover, the five amino acids insertion in the protein DNA polymerase III (alpha subunit) is distinctive to the Moraxellaceae family. Thus, the insertions evaluated constitute molecular markers useful to assess taxonomy in Pseudomonadaceae and Moraxellaceae, and also provide tools for phylogenetic studies and molecular identification of bacteria included in these important families.