Amphitrite ornata, a marine worm, contains two dehaloperoxidase genes

Amphitrite ornata, a terebellid polychaete, inhabits marine environments th at are contaminated by biogenically produced halometabolites. These halogen ated organic compounds are toxic and quite diverse. To survive in this envi ronment, A. ornata produces a novel dehaloperoxidase (DHP I) that detoxifie s haloaromatic compounds. In this study we identified and characterized two dehaloperoxidase genes, designated dhpA and dhpB, from an A. ornata comple mentary DNA library. The deduced amino acid sequences (DHP A and DHP B) of the two dhp genes both contain 137 amino acid residues, but they differ at 5 amino acid positions. Allelic variation was observed for bath genes as we ll. Polymerase chain reaction-restriction fragment length polymorphism assa ys of genomic DNA from 19 in individuals showed that each individual contai ns both the dhpA and the dhpB genes. Therefore, the two types of DHP are en coded by separate genes and are not alleles of a single gene. Furthermore, DHP A and DHP B may have different substrate specificities since they have amino acid differences in the active site.