The sequencing of the genome ofRalstonia solanacearum[Salanoubat M, Genin S, Artiguenave F,et al.(2002) Nature415, 497–502] revealed several genes that putatively code for polyphenol oxidases (PPOs). This soil-borne pathogenic bacterium withers a wide range of plants. We detected the expression of two PPO genes (accession numbers NP_518458 and NP_519622) with high similarity to tyrosinases, both containing the six conserved histidines required to bind the pair of type-3 copper ions at the active site
