ATP-dependent specificity component of the Clp protease complex. Hydrolyzes ATP. Targets specific substrates for degradation by the Clp complex. Can perform chaperone functions in the absence of CLPP. Enhances the DNA-binding activity of TFAM and is required for maintaining a normal mitochondrial nucleoid structure. ATP-dependent unfoldase that stimulates the incorporation of the pyridoxal phosphate cofactor into 5-aminolevulinate synthase, thereby activating 5-aminolevulinate (ALA) synthesis, the first step in heme biosynthesis. Important for efficient erythropoiesis through up-regulation of heme biosynthesis. Homohexamer that forms a ring structure; this hexamerization requires ATP binding. Component of the Clp complex formed by the assembly of two CLPP heptameric rings with two CLPX hexameric rings, giving rise to a symmetrical structure with two central CLPP rings flanked by a CLPX ring at either end of the complex. Interacts with TFAM. Belongs to the ClpX chaperone family.