Download MendeleyA regulatable switch mediates self-association in an immunoglobulin fold.
Calabrese, M.F., Eakin, C.M., Wang, J.M., Miranker, A.D.(2008) Nat Struct Mol Biol 15: 965-971
- PubMed: 19172750
- DOI: https://doi.org/10.1038/nsmb.1483
- Primary Citation of Related Structures:
3CIQ - PubMed Abstract:
Beta-2 microglobulin (beta2m) is a globular protein that self-associates into fibrillar amyloid deposits in patients undergoing hemodialysis therapy. Formation of these beta-sheet-rich assemblies is a fundamental property of polypeptides that can be triggered by diverse conditions. For beta2m, oligomerization into pre-amyloidogenic states occurs in specific response to coordination by Cu2+. Here we report the basis for this self-association at atomic resolution. Metal is not a direct participant in the molecular interface. Rather, binding results in distal alterations enabling the formation of two new surfaces. These interact to form a closed hexameric species. The origins of this include isomerization of a buried and conserved cis-proline previously implicated in the beta2m aggregation pathway. The consequences of this isomerization are evident and reveal a molecular basis for the conversion of this robust monomeric protein into an amyloid-competent state.
Organizational Affiliation:
Department of Molecular Biophysics and Biochemistry, Yale University, 260 Whitney Avenue, New Haven, Connecticut 06520-8114, USA.
