Functional investigation of the two ClpPs and three ClpXs in DK1622.

ClpXP is a protease complex that plays important roles in protein quality control and cell cycle regulation, but the functions of multiple ClpXs and multiple ClpPs in remain unknown. The genome of DK1622 contains two s and three s. The and genes are cotranscribed and are both essential, while the other copies are isolated in the genome and are deletable. The deletion of caused the mutant to be deficient in fruiting body development, while the gene is involved in resistance to thermal stress. Both ClpPs possess catalytic active sites, but only ClpP1 shows peptidase activity on the typical substrate Suc-LY-AMC. All of these and genes exhibit strong transcriptional upregulation in the stationary phase, and the transcription of the three genes appears to be coordinated. Our results demonstrated that multiple ClpPs and multiple ClpXs are functionally divergent and may assist in the environmental adaptation and functional diversification of .IMPORTANCEClpXP is an important protease complex of bacteria and is involved in various physiological processes. DK1622 possesses two ClpPs and three ClpXs with unclear functions. We investigated the functions of these genes and demonstrated the essential roles of and . Only ClpP1 has peptidase activity on Suc-LY-AMC, and the isolated copies participate in distinct cellular processes. All of these genes exhibited significant transcriptional upregulation in the stationary phase. Divergent functions appear in multiple ClpPs and multiple ClpXs in DK1622.