Type IV secretion systems diversity in the Acidithiobacillus genus

Abstract

Dispersal between genomes of certain mobile genetic elements and their gene cargo depends on conjugative type IV secretion systems. In this work, variants of these nanomachines, tra and trb, have been profiled in publicly available genomes of the genus Acidithiobacillus and in a set of relevant strains. Our analyses show that the trb system is of broad distribution, being present in most of the strains analyzed. In turn, the tra type is present in fewer strains of A. ferrooxidans, A. ferrivorans, A. ferriphilus and A. thiooxidans, and generally correlates with the presence of larger ICE in the respective genomes. Herein, sequence conservation, genomic context, integration site and synteny analyses are performed to infer functionality of the T4SS systems of the acidithiobacilli.