Large-scale phylogenetic mapping of bacterial secretion systems from genomes and metagenomes

To thrive, many bacteria utilize secretion systems, which are sophisticated nanomachinery that helps to proliferate and survive. With these systems, bacteria translocate proteins from their cytoplasm to an extracellular medium and/or to a target cell. The exported proteins are called effectors, as a result of the pathogenic effect they introduce into target cells. Secretion systems are generally made of several (8-25) core proteins, clustered together as an operon, and some of them are in intense research. Nevertheless, scientific literature lacks comprehensive knowledge regarding the presence/absence of a given system in a given bacteria. This work paved a pipeline to discover and map secretion systems based on their core protein sequences and characteristics. We explored genomic and metagenomic data from sources all over the world and mapped all systems found to the scale of the family phylogenetic rank. Here, are the results of T3SS (Type 3 Secretion System), T4SS, and T6SS.