Download MendeleyThree-dimensional domain swapping and supramolecular protein assembly: insights from the X-ray structure of a dimeric swapped variant of human pancreatic RNase.
Pica, A., Merlino, A., Buell, A.K., Knowles, T.P., Pizzo, E., D'Alessio, G., Sica, F., Mazzarella, L.(2013) Acta Crystallogr D Biol Crystallogr 69: 2116-2123
- PubMed: 24100329
- DOI: https://doi.org/10.1107/S0907444913020507
- Primary Citation of Related Structures:
4KXH - PubMed Abstract:
The deletion of five residues in the loop connecting the N-terminal helix to the core of monomeric human pancreatic ribonuclease leads to the formation of an enzymatically active domain-swapped dimer (desHP). The crystal structure of desHP reveals the generation of an intriguing fibril-like aggregate of desHP molecules that extends along the c crystallographic axis. Dimers are formed by three-dimensional domain swapping. Tetramers are formed by the aggregation of swapped dimers with slightly different quaternary structures. The tetramers interact in such a way as to form an infinite rod-like structure that propagates throughout the crystal. The observed supramolecular assembly captured in the crystal predicts that desHP fibrils could form in solution; this has been confirmed by atomic force microscopy. These results provide new evidence that three-dimensional domain swapping can be a mechanism for the formation of elaborate large assemblies in which the protein, apart from the swapping, retains its original fold.
Organizational Affiliation:
Department of Chemical Sciences, University of Naples `Federico II', Via Cintia, 80126 Naples, Italy.
