The prodigiosin biosynthetic gene cluster (pig cluster) of Serratia marcescens ATCC 274 (Sma 274) is flanked by cueR/copA homologues. Inactivation of the copA homologue resulted in an increased sensitivity to copper, confirming that CopA is involved in copper homeostasis in Sma 274. The affect of copper on the biosynthesis of prodigiosin in Sma 274 and the copA mutant strain was investigated. Increased levels of copper were found to reduce prodigiosin production in the wild type Sma 274, but increase production in the copA mutant strain. The physiological implications for CopA mediated prodigiosin production are discussed. We also demonstrate that the gene products of pigB-pigE of Sma 274 are sufficient for the biosynthesis of 2-methyl-3-n-amyl-pyrrole (MAP) and condensation with 4-methoxy-2,2'-bipyrrole-5-carboxyaldehyde (MBC) to form prodigiosin, as we have shown for Serratia sp. ATCC 39006.
Department of Chemistry
University of Cambridge