ジャーナル: Nat Microbiol / 年: 2022 タイトル: Identification and structure of an extracellular contractile injection system from the marine bacterium Algoriphagus machipongonensis. 著者: Jingwei Xu / Charles F Ericson / Yun-Wei Lien / Florentine U N Rutaganira / Fabian Eisenstein / Miki Feldmüller / Nicole King / Martin Pilhofer / 要旨: Contractile injection systems (CISs) are phage tail-like nanomachines, mediating bacterial cell-cell interactions as either type VI secretion systems (T6SSs) or extracellular CISs (eCISs). ...Contractile injection systems (CISs) are phage tail-like nanomachines, mediating bacterial cell-cell interactions as either type VI secretion systems (T6SSs) or extracellular CISs (eCISs). Bioinformatic studies uncovered a phylogenetic group of hundreds of putative CIS gene clusters that are highly diverse and widespread; however, only four systems have been characterized. Here we studied a putative CIS gene cluster in the marine bacterium Algoriphagus machipongonensis. Using an integrative approach, we show that the system is compatible with an eCIS mode of action. Our cryo-electron microscopy structure revealed several features that differ from those seen in other CISs: a 'cap adaptor' located at the distal end, a 'plug' exposed to the tube lumen, and a 'cage' formed by massive extensions of the baseplate. These elements are conserved in other CISs, and our genetic tools identified that they are required for assembly, cargo loading and function. Furthermore, our atomic model highlights specific evolutionary hotspots and will serve as a framework for understanding and re-engineering CISs.
3A: Putative phage tail sheath protein FI 3B: Putative phage tail sheath protein FI 3C: Putative phage tail sheath protein FI 3D: Putative phage tail sheath protein FI 3E: Putative phage tail sheath protein FI 3F: Putative phage tail sheath protein FI 4A: Putative phage tail sheath protein FI 4B: Putative phage tail sheath protein FI 4C: Putative phage tail sheath protein FI 4D: Putative phage tail sheath protein FI 4E: Putative phage tail sheath protein FI 4F: Putative phage tail sheath protein FI 5A: Putative phage tail sheath protein FI 5B: Putative phage tail sheath protein FI 5C: Putative phage tail sheath protein FI 5D: Putative phage tail sheath protein FI 5E: Putative phage tail sheath protein FI 5F: Putative phage tail sheath protein FI
分子量: 76319.039 Da / 分子数: 18 / 由来タイプ: 天然 詳細: the residues 288-320aa are not built up in the model due to the poor map density, with residues 430-446aa assigned by poly-alanine chain. 由来: (天然) Algoriphagus machipongonensis (バクテリア) 参照: UniProt: A3HTC2
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実験情報
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実験
実験
手法: 電子顕微鏡法
EM実験
試料の集合状態: PARTICLE / 3次元再構成法: らせん対称体再構成法
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試料調製
構成要素
名称: The contracted sheath shell of an extracellular contractile injection system in marine bacterium Algoriphagus machipongonensis. タイプ: COMPLEX / Entity ID: all / 由来: NATURAL