Roles of the type IV secretion systems in bacterial resistance to heavy metals

Abstract:

The type IV secretion systems (T4SSs) are ubiquitous and versatile in bacteria, capable of transporting proteins, DNA, and protein-DNA complexes. Bacterial conjugation is a key mechanism of horizontal gene transfer. T4SSs can mediate the transfer of conjugative plasmids or integrative elements from one bacterium to another, which endow bacteria with new genes and functions. The acquisition of genes in this way not only enables bacteria to gain new functions but also helps them occupy niches, promoting the adaptation of bacteria to a new or changing environment. This article summarizes the roles of T4SSs, especially in bacterial adaptation to heavy metal-polluted environments.