Structural basis of N-end rule substrate recognition in Escherichia coli by the ClpAP adaptor protein ClpS.

ABSTRACT: In Escherichia coli, the ClpAP protease, together with the adaptor protein ClpS, is responsible for the degradation of proteins bearing an amino-terminal destabilizing amino acid (N-degron). Here, we determined the three-dimensional structures of ClpS in complex with three peptides, each having a different destabilizing residue--Leu, Phe or Trp--at its N terminus. All peptides, regardless of the identity of their N-terminal residue, are bound in a surface pocket on ClpS in a stereo-specific manner. Several highly conserved residues in this binding pocket interact directly with the backbone of the N-degron peptide and hence are crucial for the binding of all N-degrons. By contrast, two hydrophobic residues define the volume of the binding pocket and influence the specificity of ClpS. Taken

SUBMITTER: Schuenemann VJ 

PROVIDER: S-EPMC2680879 | biostudies-literature | 2009 May

REPOSITORIES: biostudies-literature