Aromatic degradation in bacteria is a complex phenomenon involving not only catabolic enzymes but also several auxiliary proteins. Some of them are located in the inner or outer membranes and are connected with both intracellular pH homeostasis and uptake of aromatic molecules. Little is known about how hydrophobic substances, such as aromatic hydrocarbons destined for biodegradation, are transported across membranes. Recently studies have been shown that the growth of a new Pseudomonas strain in phenol as sole carbon and energy source induce the expression of two membrane proteins. We identified a membrane protein involved in aromatic hydrocarbon degradation as well as a probable porin, which may, in fact, function as an aromatic compound specific porin.
The goal of this proposal is the structural analysis of membrane proteins involved in the transport of aromatic compounds, which is essential for a better understanding of protein functions as for the transport of molecules across the membrane. The strain will be grown on aromatic compound as sole carbon and energy source. Methods for the fractionation of the membranes will apply for the separation of the outer and inner membrane. Attempts for the isolation of the overexpressed membrane proteins in a homogenous form will be the first step for the structural characterisation. Study of the bacterial membrane proteome, though in its early stages, is a field of growing interest in the search for information about nutrient transport and processing as of their implication in bioremediation.