The clpP multigene family for the ATP-dependent Clp protease in the cyanobacterium Synechococcus.

摘要: In the cyanobacterium Synechococcus sp. strain PCC 7942 a multigene family of three different isozymes encodes proteolytic subunit ClpP ATP-dependent Clp protease. contrast to monocistronic clpPI gene, clpPII and clpPIII are part two bicistronic operons with clpX clpR, respectively. Unlike most bacterial proteins, ClpP2, ClpP3, ClpR ClpX proteins were not highly inducible by high temperatures, or other stresses such as cold, light oxidation, although slower gradual rises occurred for all four during light, at low temperature. Attempts inactivate clpPII, clpIII, clpR genes only successful suggesting others essential cell viability. The DeltaclpPII mutant exhibited no significant phenotypic changes from wild-type, including change in content. Despite apparent arrangement both clpPII-clpX clpR-clpPIII, primarily produce transcripts, polycistronic transcripts detected. Mapping 5' ends revealed promoters situated within 3' region Transcriptional translational studies further showed differences expression regulation between clpP-clpR-clpX genes. Inactivation caused decrease ClpP2 protein concomitant small increases ClpP3 ClpR. resulted large rise but lesser extent ClpP1 protein. Similar also DeltaclpPII. These results highlight regulatory complexity these multiple clp their functional importance cyanobacteria.