InterPro domain: IPR022935

This entry includes ClpS from bacteria and chloroplastic CLPS1/2 from plants. ClpS binds directly to N-terminal destabilising residues through its substrate-binding site distal to the ClpS-ClpA interface, and targets these substrates to the ClpAP protease for degradation [ 1 , 2 ].

ClpS is a small alpha/beta protein that consists of three alpha-helices connected to three antiparallel beta-strands [ 3 ]. The protein has a globular shape, with a curved layer of three antiparallel alpha-helices over a twisted antiparallel beta-sheet. Dimerization of ClpS may occur through its N-terminal domain. This short extended N-terminal region in ClpS is followed by the central seven-residue beta-strand, which is flanked by two other beta-strands in a small beta-sheet.

1. ClpS is an essential component of the N-end rule pathway in Escherichia coli. Nature 439, 753-6
2. ClpS1 is a conserved substrate selector for the chloroplast Clp protease system in Arabidopsis. Plant Cell 25, 2276-301
3. Structural analysis of the adaptor protein ClpS in complex with the N-terminal domain of ClpA. Nat. Struct. Biol. 9, 906-11