To better understand their function, we study the molecular architecture of two types of bacterial secretion systems, namely type II (T2SS) and type VI (T6SS). We undertook first the systematic study of the interaction network of five pseudopilins from Pseudomonas aeruginosa T2SS by surface plasmon resonance (PMID:19828448) . This study confirmed the existence within this system of a XcpV(I)-W(J)-X(K) heterotrimer, previously observed by X-ray crystallography. But the study has also suggested the possibility of a tetrameric complex that would add XcpU(H) to the end of the pseudopilus.
In a second step, we are studying the structures of several components of T2SS and T6SS. We expect that these structures will give us clues to design molecules able to block the assembly of the secretion systems, thus allowing the selective targeting of specific bacterial infections.