5B7C

Crystal structure of octopus S-crystallin Q108F mutant in complex with glutathione

5B7C の概要

• エントリーDOI: 10.2210/pdb5b7c/pdb
• 分子名称: S-crystallin OctvuS4, GLUTATHIONE, SULFATE ION, ... (4 entities in total)
• 機能のキーワード: lens-refractive protein, structural protein
• 由来する生物種: Octopus vulgaris (common octopus)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 28431.74

構造登録者

Chou, C.-Y.,Tan, W.-H.,Wu, C.-G. (登録日: 2016-06-07, 公開日: 2016-08-03, 最終更新日: 2024-04-03)

主引用文献

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

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: 27499004
DOI: 10.1038/srep31176

実験手法

X-RAY DIFFRACTION (2.35 Å)