Description
Gene expression in response to changes in sulfur supply was studied in P. aeruginosa E601, a cystic fibrosis isolate that displays mucin sulfatase activity, and in P. aeruginosa PAO1. A large family of genes was found to be upregulated by sulfate limitation in both isolates, encoding sulfatases and sulfonatases, transport systems, oxidative stress proteins, and a sulfate-regulated TonB/ExbBD complex. These genes were localized in five distinct islands on the genome, and encoded proteins with a significantly reduced content of cysteine and methionine. Growth of P. aeruginosa E601 with mucin as sulfur source led to a sulfate starvation response, but also to induction of genes involved with type III secretion systems.