3GW1

The structure of the Caulobacter crescentus CLPs protease adaptor protein in complex with FGG tripeptide

Summary for 3GW1

• Entry DOI: 10.2210/pdb3gw1/pdb
• Related: 3DNJ 3G19 3G1B 3GQ0 3GQ1
• Descriptor: ATP-dependent Clp protease adapter protein ClpS, FGG peptide, MAGNESIUM ION, ... (4 entities in total)
• Functional Keywords: adaptor, protein-peptide complex, peptide-binding protein, peptide binding protein
• Biological source: Caulobacter vibrioides; More
• Total number of polymer chains: 4
• Total formula weight: 20471.58

Authors

Baker, T.A.,Roman-Hernandez, G.,Sauer, R.T.,Grant, R.A. (deposition date: 2009-03-31, release date: 2009-05-05, Last modification date: 2023-09-06)

Primary citation

Roman-Hernandez, G.,Grant, R.A.,Sauer, R.T.,Baker, T.A.
Molecular basis of substrate selection by the N-end rule adaptor protein ClpS.
Proc.Natl.Acad.Sci.USA, 106:8888-8893, 2009

PubMed Abstract: The N-end rule is a conserved degradation pathway that relates the stability of a protein to its N-terminal amino acid. Here, we present crystal structures of ClpS, the bacterial N-end rule adaptor, alone and engaged with peptides containing N-terminal phenylalanine, leucine, and tryptophan. These structures, together with a previous structure of ClpS bound to an N-terminal tyrosine, illustrate the molecular basis of recognition of the complete set of primary N-end rule amino acids. In each case, the alpha-amino group and side chain of the N-terminal residue are the major determinants of recognition. The binding pocket for the N-end residue is preformed in the free adaptor, and only small adjustments are needed to accommodate N-end rule residues having substantially different sizes and shapes. M53A ClpS is known to mediate degradation of an expanded repertoire of substrates, including those with N-terminal valine or isoleucine. A structure of Met53A ClpS engaged with an N-end rule tryptophan reveals an essentially wild-type mechanism of recognition, indicating that the Met(53) side chain directly enforces specificity by clashing with and excluding beta-branched side chains. Finally, experimental and structural data suggest mechanisms that make proteins with N-terminal methionine bind very poorly to ClpS, explaining why these high-abundance proteins are not degraded via the N-end rule pathway in the cell.

PubMed: 19451643
DOI: 10.1073/pnas.0903614106

Experimental method

X-RAY DIFFRACTION (2.36 Å)