5B7C
Crystal structure of octopus S-crystallin Q108F mutant in complex with glutathione
Summary for 5B7C
| Entry DOI | 10.2210/pdb5b7c/pdb |
| Descriptor | S-crystallin OctvuS4, GLUTATHIONE, SULFATE ION, ... (4 entities in total) |
| Functional Keywords | lens-refractive protein, structural protein |
| Biological source | Octopus vulgaris (common octopus) |
| Total number of polymer chains | 1 |
| Total formula weight | 28431.74 |
| Authors | Chou, C.-Y.,Tan, W.-H.,Wu, C.-G. (deposition date: 2016-06-07, release date: 2016-08-03, Last modification date: 2024-04-03) |
| Primary citation | Tan, W.H.,Cheng, S.C.,Liu, Y.T.,Wu, C.G.,Lin, M.H.,Chen, C.C.,Lin, C.H.,Chou, C.Y. Structure of a Highly Active Cephalopod S-crystallin Mutant: New Molecular Evidence for Evolution from an Active Enzyme into Lens-Refractive Protein. Sci Rep, 6:31176-31176, 2016 Cited by PubMed Abstract: Crystallins are found widely in animal lenses and have important functions due to their refractive properties. In the coleoid cephalopods, a lens with a graded refractive index provides good vision and is required for survival. Cephalopod S-crystallin is thought to have evolved from glutathione S-transferase (GST) with various homologs differentially expressed in the lens. However, there is no direct structural information that helps to delineate the mechanisms by which S-crystallin could have evolved. Here we report the structural and biochemical characterization of novel S-crystallin-glutathione complex. The 2.35-Å crystal structure of a S-crystallin mutant from Octopus vulgaris reveals an active-site architecture that is different from that of GST. S-crystallin has a preference for glutathione binding, although almost lost its GST enzymatic activity. We've also identified four historical mutations that are able to produce a "GST-like" S-crystallin that has regained activity. This protein recapitulates the evolution of S-crystallin from GST. Protein stability studies suggest that S-crystallin is stabilized by glutathione binding to prevent its aggregation; this contrasts with GST-σ, which do not possess this protection. We suggest that a tradeoff between enzyme activity and the stability of the lens protein might have been one of the major driving force behind lens evolution. PubMed: 27499004DOI: 10.1038/srep31176 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.35 Å) |
Structure validation
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