ジャーナル: ISME J / 年: 2025 タイトル: Thermophilic bacteria employ a contractile injection system in hot spring microbial mats. 著者: Vasil A Gaisin / Corina Hadjicharalambous / Izabela Mujakić / Cristian Villena-Alemany / Jiangning Li / Michal Koblížek / Martin Pilhofer / 要旨: Bacterial contractile injection systems (CISs) are multiprotein complexes that facilitate the bacterial response to environmental factors or interactions with other organisms. Multiple novel CISs ...Bacterial contractile injection systems (CISs) are multiprotein complexes that facilitate the bacterial response to environmental factors or interactions with other organisms. Multiple novel CISs have been characterised in laboratory bacterial cultures recently; however, studying CISs in the context of the native microbial community remains challenging. Here, we present an approach to characterise a bioinformatically predicted CIS by directly analysing bacterial cells from their natural environment. Using cryo-focused ion beam milling and cryo-electron tomography (cryoET) imaging, guided by 16S rRNA gene amplicon sequencing, we discovered that thermophilic Chloroflexota bacteria produce intracellular CIS particles in a natural hot spring microbial mat. We then found a niche-specific production of CIS in the structured microbial community using an approach combining metagenomics, proteomics, and immunogold staining. Bioinformatic analysis and imaging revealed CISs in other extremophilic Chloroflexota and Deinococcota. This Chloroflexota/Deinococcota CIS lineage shows phylogenetic and structural similarity to previously described cytoplasmic CIS from Streptomyces and probably shares the same cytoplasmic mode of action. Our integrated environmental cryoET approach is suitable for discovering and characterising novel macromolecular complexes in environmental samples.
A: 13854.72 Å / B: 19483.2 Å / C: 4059.0 Å α=β=γ: 90.0 °
-
添付データ
-
試料の構成要素
-
全体 : Contracted contractile injection system in lysed Roseiflexus cell...
全体
名称: Contracted contractile injection system in lysed Roseiflexus cell from microbial mat
要素
細胞: Contracted contractile injection system in lysed Roseiflexus cell from microbial mat
-
超分子 #1: Contracted contractile injection system in lysed Roseiflexus cell...
超分子
名称: Contracted contractile injection system in lysed Roseiflexus cell from microbial mat タイプ: cell / ID: 1 / 親要素: 0
由来(天然)
生物種: Roseiflexus (バクテリア)
-
実験情報
-
構造解析
手法
クライオ電子顕微鏡法
解析
電子線トモグラフィー法
試料の集合状態
cell
-
試料調製
緩衝液
pH: 7.5
凍結
凍結剤: ETHANE-PROPANE
切片作成
集束イオンビーム - 装置: OTHER / 集束イオンビーム - イオン: OTHER / 集束イオンビーム - 電圧: 30 / 集束イオンビーム - 電流: 0.05 / 集束イオンビーム - 時間: 360 / 集束イオンビーム - 温度: 123 K / 集束イオンビーム - Initial thickness: 1000 / 集束イオンビーム - 最終 厚さ: 180 集束イオンビーム - 詳細: The value given for _em_focused_ion_beam.instrument is Zeiss Crossbeam. This is not in a list of allowed values {'OTHER', 'DB235'} so OTHER is written into the XML file.
-
電子顕微鏡法
顕微鏡
TFS KRIOS
撮影
フィルム・検出器のモデル: GATAN K3 BIOCONTINUUM (6k x 4k) 平均電子線量: 2.247 e/Å2