3D domain swapping: A mechanism for oligomer assembly

Authors

  • Melanie J. Bennett,

    1. Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104–6059
    2. Molecular Biology Institute, Department of Chemistry and Biochemistry, and UCLA-DOE Laboratory of Structural Biology and Molecular Medicine, University of California —Los Angeles, Los Angeles, California 90095-1570
    Search for more papers by this author
  • Michael P. Schlunegger,

    1. Molecular Biology Institute, Department of Chemistry and Biochemistry, and UCLA-DOE Laboratory of Structural Biology and Molecular Medicine, University of California —Los Angeles, Los Angeles, California 90095-1570
    Search for more papers by this author
  • David Eisenberg

    Corresponding author
    1. Molecular Biology Institute, Department of Chemistry and Biochemistry, and UCLA-DOE Laboratory of Structural Biology and Molecular Medicine, University of California —Los Angeles, Los Angeles, California 90095-1570
    • Molecular Biology Institute, Department of Chemistry and Biochemistry, and UCLA-DOE Laboratory of Structural Biology and Molecular Medicine, University of California —Los Angeles, Los Angeles, California 90095-1570
    Search for more papers by this author

Abstract

3D domain swapping is a mechanism for forming oligomeric proteins from their monomers. In 3D domain swapping, one domain of a monomeric protein is replaced by the same domain from an identical protein chain. The result is an intertwined dimer or higher oligomer, with one domain of each subunit replaced by the identical domain from another subunit. The swapped “domain” can be as large as an entire tertiary globular domain, or as small as an α-helix or a strand of a β-sheet. Examples of 3D domain swapping are reviewed that suggest domain swapping can serve as a mechanism for functional interconversion between monomers and oligomers, and that domain swapping may serve as a mechanism for evolution of some oligomeric proteins. Domain-swapped proteins present examples of a single protein chain folding into two distinct structures.

Ancillary