My research interest is ICEclc, an Integrative and Conjugative Element present in two identical copies in the bacterium Pseudomonas knackmussii B13, the first bacterium known to degrade chloroaromatic compounds such as 3-chlorobenzoate (3CBA). ICEclc is ‘special’, because it encodes the enzymes for 3CBA metabolism. ICEclc is further ‘special’, because it can self-transfer to other bacterial species, but only when it ‘transforms’ the host cell to an ICE-transfer machine. Curiously, only 3-5% of individual cells in stationary phase develop this state; in the others, nothing seems to happen.
The aim of my project is to unravel the network of regulatory decisions that lead to ICEclc activation. I have co-discovered nine specific genes and gene clusters on ICEclc, which coordinately become activated for ICE transfer. I am now studying how these promoters become activated and which specific sequence elements are important for determining this bistable activation.