Caseinolytic Peptidase B (CLPB)

SKD3, encodes a putative 76-kDa protein of 677 amino acids (aa). The deduced aa sequence of the SKD3 polypeptide contains four ankyrin-like repeats in the N-terminal domain and a single ATP-binding consensus site in the C-terminal domain. The 378-aa C-terminal domain of SKD3 has 57-64% similarity with members of the Clp/HSP104 family, including the ClpA regulatory subunit of the Clp protease and S. cerevisiae heat-shock protein 104. SKD3 transcript is present in a wide variety of tissues, is abundant in mouse heart, skeletal muscle and kidney, and is most abundant in testis. Members of the Clp/HSP104 family have been identified previously from bacteria, yeast and chloroplasts, and are ATPases regulating Clp protease activity and specificity, or mediating cellular responses involved in thermotolerance.