A model for heterooligomer formation in the heat shock response of Escherichia coli

Small heat shock proteins (sHsp) are widely distributed molecular chaperones that bind to misfolded proteins to prevent irreversible aggregation and aid in refolding to a competent state. The sHsps characterized thus far all contain a conserved α-crystallin, and variable N- and C-termini critical for chaperone activity and oligomerization. The Escherichia coli sHsps IbpA and IbpB share 48% sequence homology, are induced by heat shock and oxidative stress, and each requires the presence of the other to effect protein protection. Molecular Dynamics (MD) simulations of homology-modeled monomers and heterooligomers of these sHsps identify a possible mechanism for cooperation between IbpA and IbpB.

Figure optionsDownload as PowerPoint slideHighlights
► Molecular Dynamics simulations of Escherichia coli sHsps IbpA and IbpB.
► Solvent exclusion identified as a critical factor driving heterooligomer formation.
► Mechanism of heat activation of IbpA linked to formation of IbpAIbpB heterooligomer.