4KXH

The X-ray crystal structure of a dimeric variant of human pancreatic ribonuclease

Summary for 4KXH

• Entry DOI: 10.2210/pdb4kxh/pdb
• Descriptor: Ribonuclease pancreatic, SULFATE ION, SODIUM ION, ... (5 entities in total)
• Functional Keywords: hydrolase
• Biological source: Homo sapiens (human)
• Cellular location: Secreted: P07998
• Total number of polymer chains: 4
• Total formula weight: 57849.09

Authors

Pica, A.,Merlino, A.,Mazzarella, L.,Sica, F. (deposition date: 2013-05-26, release date: 2013-10-02, Last modification date: 2017-11-15)

Primary citation

Pica, A.,Merlino, A.,Buell, A.K.,Knowles, T.P.,Pizzo, E.,D'Alessio, G.,Sica, F.,Mazzarella, L.
Three-dimensional domain swapping and supramolecular protein assembly: insights from the X-ray structure of a dimeric swapped variant of human pancreatic RNase.
Acta Crystallogr.,Sect.D, 69:2116-2123, 2013

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.

PubMed: 24100329
DOI: 10.1107/S0907444913020507

Experimental method

X-RAY DIFFRACTION (2.7 Å)