Description:

Title: The Amazing Structural and Functional Diversity of Bacterial Type IV Secretion Systems

Speaker: Peter Christie, PhD / University of Texas, Houston

Host: Nicholas Cianciotto, PhD

Topic:

The type IV secretion systems (T4SSs) are a functionally and structurally diverse superfamily of translocation machines deployed by many species of bacteria to aid in colonization and infection. This talk will summarize recent advances in structural definition of several T4SS nanomachines, including most recently, the pKM101-encoded Tra T4SS in the native context of the Escherichia coli cell envelope. Comparisons of these nanomachines offer a unified view of how substrates engage with and are translocated via T4SSs to target cells. We also recently discovered that the F plasmid-encoded T4SS translocates several proteins to recipient cells with the biological outcome of suppressing the mating-induced SOS response. We propose that conjugation-mediated protein trafficking represents a previously unrecognized form of intercellular communication affecting both genome evolution and development of microbial communities.