COPPER HYPERSENSITIVITY AND UPTAKE IN PSEUDOMONAS-SYRINGAE CONTAININGCLONED COMPONENTS OF THE COPPER RESISTANCE OPERON

Copper resistance in Pseudomonas syringae carrying the copABCD operon is associated with accumulation of copper in the periplasm and outer m embrane, apparently as a function of the copper-binding activities of the copABC gene products. However, no specific function for copD has b een determined. In this study, P. syringae cells containing copCD or c opBCD cloned behind the lac promoter were hypersensitive to copper. An increased accumulation of copper was measured in cells containing sev eral combinations of cop genes that included copC and copD. Our data s uggest that CopC, a periplasmic copper-binding protein, and CopD, a pr obable inner membrane protein, may function together in copper uptake.