6QMN
Crystal structure of a Ribonuclease A-Onconase chimera
Summary for 6QMN
| Entry DOI | 10.2210/pdb6qmn/pdb |
| Descriptor | Ribonuclease pancreatic, PHOSPHATE ION (3 entities in total) |
| Functional Keywords | pancreatic ribonuclease a, alpha/beta fold, chimera, hydrolase |
| Biological source | Bison bison (American bison) |
| Total number of polymer chains | 3 |
| Total formula weight | 40758.09 |
| Authors | Esposito, L.,Vitagliano, L.,Ruggiero, A.,Picone, D.,Leone, S.,Donnarumma, F. (deposition date: 2019-02-07, release date: 2019-05-08, Last modification date: 2024-10-16) |
| Primary citation | Esposito, L.,Donnarumma, F.,Ruggiero, A.,Leone, S.,Vitagliano, L.,Picone, D. Structure, stability and aggregation propensity of a Ribonuclease A-Onconase chimera. Int.J.Biol.Macromol., 133:1125-1133, 2019 Cited by PubMed Abstract: Structural roles of loop regions are frequently overlooked in proteins. Nevertheless, they may be key players in the definition of protein topology and in the self-assembly processes occurring through domain swapping. We here investigate the effects on structure and stability of replacing the loop connecting the last two β-strands of RNase A with the corresponding region of the more thermostable Onconase. The crystal structure of this chimeric variant (RNaseA-ONC) shows that its terminal loop size better adheres to the topological rules for the design of stabilized proteins, proposed by Baker and coworkers [43]. Indeed, RNaseA-ONC displays a thermal stability close to that of RNase A, despite the lack of Pro at position 114, which, due to its propensity to favor a cis peptide bond, has been identified as an important stabilizing factor of the native protein. Accordingly, RNaseA-ONC is significantly more stable than RNase A variants lacking Pro114; RNaseA-ONC also displays a higher propensity to form oligomers in native conditions when compared to either RNase A or Onconase. This finding demonstrates that modifications of terminal loops should to be carefully controlled in terms of size and sequence to avoid unwanted and/or potentially harmful aggregation processes. PubMed: 31026530DOI: 10.1016/j.ijbiomac.2019.04.164 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.31 Å) |
Structure validation
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