Plasmid-mediated UV-protection in Myxococcus xanthus.

Plasmid R46 was successfully transferred from Escherichia coli K=12 into myxococcus xanthus strain MD-1 but not into M. xanthus strain XK. Plasmid R68.45 was transferred from E. coli K-12 into both strains of M. xanthus. The effects of these plasmids on survival of M. xanthus after ultraviolet (UV)-244 nm irradiation, the ability of M. xanthus to reactivate irradiated myxophages, and weigle reactivation of UV-irradiated effect on UV survival of M. xanthus, but increased the host's ability to reactivation irradiated myxophages. Plasmid R68.45 protected M. xanthus strains MD-1 and XK against the lethal effects of UV irradiation and also increased the host's ability to reactivate irradiated myxophages.