ジャーナル: J Biol Chem / 年: 2023 タイトル: The SDBC is active in quenching oxidative conditions and bridges the cell envelope layers in Deinococcus radiodurans. 著者: Domenica Farci / André T Graça / Luca Iesu / Daniele de Sanctis / Dario Piano / 要旨: Deinococcus radiodurans is known for its remarkable ability to withstand harsh stressful conditions. The outermost layer of its cell envelope is a proteinaceous coat, the S-layer, essential for ...Deinococcus radiodurans is known for its remarkable ability to withstand harsh stressful conditions. The outermost layer of its cell envelope is a proteinaceous coat, the S-layer, essential for resistance to and interactions with the environment. The S-layer Deinoxanthin-binding complex (SDBC), one of the main units of the characteristic multilayered cell envelope of this bacterium, protects against environmental stressors and allows exchanges with the environment. So far, specific regions of this complex, the collar and the stalk, remained unassigned. Here, these regions are resolved by cryo-EM and locally refined. The resulting 3D map shows that the collar region of this multiprotein complex is a trimer of the protein DR_0644, a Cu-only superoxide dismutase (SOD) identified here to be efficient in quenching reactive oxygen species. The same data also showed that the stalk region consists of a coiled coil that extends into the cell envelope for ∼280 Å, reaching the inner membrane. Finally, the orientation and localization of the complex are defined by in situ cryo-electron crystallography. The structural organization of the SDBC couples fundamental UV antenna properties with the presence of a Cu-only SOD, showing here coexisting photoprotective and chemoprotective functions. These features suggests how the SDBC and similar protein complexes, might have played a primary role as evolutive templates for the origin of photoautotrophic processes by combining primary protective needs with more independent energetic strategies.
A: 525.156 Å / B: 525.156 Å / C: 575.054 Å α=β=γ: 90.0 °
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添付データ
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試料の構成要素
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全体 : SDBC and SOD assembly, composite map
全体
名称: SDBC and SOD assembly, composite map
要素
複合体: SDBC and SOD assembly, composite map
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超分子 #1: SDBC and SOD assembly, composite map
超分子
名称: SDBC and SOD assembly, composite map / タイプ: complex / ID: 1 / キメラ: Yes / 親要素: 0 / 含まれる分子: #1 詳細: This map is a composite map of the maps with deposition codes EMD-15382 and EMD-15384, and it is the composite map for the model with deposition code PDB-8AGD. The map has to be used as a ...詳細: This map is a composite map of the maps with deposition codes EMD-15382 and EMD-15384, and it is the composite map for the model with deposition code PDB-8AGD. The map has to be used as a consensus map of the full structure (PDB-8AGD).
フィルム・検出器のモデル: GATAN K2 QUANTUM (4k x 4k) 平均電子線量: 1.3 e/Å2
実験機器
モデル: Titan Krios / 画像提供: FEI Company
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画像解析
初期 角度割当
タイプ: MAXIMUM LIKELIHOOD
最終 角度割当
タイプ: MAXIMUM LIKELIHOOD
最終 再構成
解像度のタイプ: BY AUTHOR / 解像度: 3.5 Å / 解像度の算出法: FSC 0.143 CUT-OFF 詳細: This map is a composite map of the maps with deposition codes EMD-15382 and EMD-15384, and it is the composite map for the model with deposition code PDB-8AGD. This map is a composite map of ...詳細: This map is a composite map of the maps with deposition codes EMD-15382 and EMD-15384, and it is the composite map for the model with deposition code PDB-8AGD. This map is a composite map of the maps with deposition codes EMD-15382 and EMD-15384, and it is the composite map for the model with deposition code PDB-8AGD. The map has to be used as a consensus map of the full structure (PDB-8AGD). 使用した粒子像数: 252122