2ZA4
Crystal Structural Analysis of Barnase-barstar Complex
Summary for 2ZA4
| Entry DOI | 10.2210/pdb2za4/pdb |
| Related | 1X1U 1X1W 1X1X 1X1Y |
| Descriptor | Ribonuclease, Barstar, CHLORIDE ION, ... (4 entities in total) |
| Functional Keywords | protein-protein complex, endonuclease, genetically modified food, hydrolase, nuclease, secreted, cytoplasm, hydrolase-hydrolase inhibitor complex, hydrolase/hydrolase inhibitor |
| Biological source | Bacillus amyloliquefaciens More |
| Cellular location | Secreted: P00648 Cytoplasm: P11540 |
| Total number of polymer chains | 4 |
| Total formula weight | 45241.34 |
| Authors | Urakubo, Y.,Ikura, T.,Ito, N. (deposition date: 2007-10-01, release date: 2008-05-20, Last modification date: 2023-11-01) |
| Primary citation | Urakubo, Y.,Ikura, T.,Ito, N. Crystal structural analysis of protein-protein interactions drastically destabilized by a single mutation Protein Sci., 17:1055-1065, 2008 Cited by PubMed Abstract: The complex of barnase (bn) and barstar (bs), which has been widely studied as a model for quantitative analysis of protein-protein interactions, is significantly destabilized by a single mutation, namely, bs Asp39 --> Ala, which corresponds to a change of 7.7 kcal x mol(-1) in the free energy of binding. However, there has been no structural information available to explain such a drastic destabilization. In the present study, we determined the structure of the mutant complex at 1.58 A resolution by X-ray crystallography. The complex was similar to the wild-type complex in terms of overall and interface structures; however, the hydrogen bond network mediated by water molecules at the interface was significantly different. Several water molecules filled the cavity created by the mutation and consequently caused rearrangement of the hydrated water molecules at the interface. The water molecules were redistributed into a channel-like structure that penetrated into the complex. Furthermore, molecular dynamics simulations showed that the mutation increased the mobility of water molecules at the interface. Since such a drastic change in hydration was not observed in other mutant complexes of bn and bs, the significant destabilization of the interaction may be due to this channel-like structure of hydrated water molecules. PubMed: 18441234DOI: 10.1110/ps.073322508 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.58 Å) |
Structure validation
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