Tn5563, a transposon encoding putative mercuric ion transport proteins located on plasmid pRA2 of Pseudomonas alcaligenes.
Sequence analysis of pRA2, an endogenous 33-kb plasmid from Pseudomonas alcaligenes NCIB 9867 (strain P25X), revealed the presence of a 6256-bp transposon of the Tn3 family, designated Tn5563. Tn5563, which is flanked by two 39-bp inverted repeats, encodes a transposase, a resolvase, and two open reading frames which share amino acid sequence similarities with the mercuric ion transport proteins MerT and MerP encoded by several mer operons. However, no other mer operon genes were found on Tn5563. Sequencing of a RP4::XIn hybrid plasmid indicates possible interactions between pRA2 and the P25X chromosome mediated by Tn5563.