Heat shock protein substrate specificity

Photocrosslinkers have been incorporated in E. coli to confirm close contact between specific residues of a protein and its substrate. ClpB, a heat shock protein that aids in the disaggregation and refolding of proteins during the heat shock response, has a conserved aromatic residue (Tyr251) in the central pore of its AAA+ domain, considered to be the main substrate recognition residue. " After Tyr251 in ClpB was replaced with />BpA, biotinylated substrate peptides were shown to be crosslinked upon UV light exposure, but not if BpA was incorporated elsewhere in the AAA+ domain of this protein. 

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