Regions of the megaplasmid DNA relevant to the cation-efflux pump were sequenced; however, to the best of our knowledge, none of the groups is systematically sequencing any of the plasmids. The complete sequence of the megaplasmids will be instrumental in understanding gene organization, especially mechanism of plasmid replication, partition and transfer, and allowing the construction of environmentally-friendly bacteria e.g. E.coli with stable and efficient mechanism for heavy-metal resistance.