Electron cryo-microscopy reveals the structure of the archaeal thread filament.
Matthew C GainesMichail N IsupovShamphavi SivabalasarmaRisat Ul HaqueMathew McLarenClara L MollatPatrick TrippAlexander NeuhausVicki A M GoldSonja-Verena AlbersBertram DaumPublished in: Nature communications (2022)
Pili are filamentous surface extensions that play roles in bacterial and archaeal cellular processes such as adhesion, biofilm formation, motility, cell-cell communication, DNA uptake and horizontal gene transfer. The model archaeaon Sulfolobus acidocaldarius assembles three filaments of the type-IV pilus superfamily (archaella, archaeal adhesion pili and UV-inducible pili), as well as a so-far uncharacterised fourth filament, named "thread". Here, we report on the cryo-EM structure of the archaeal thread. The filament is highly glycosylated and consists of subunits of the protein Saci_0406, arranged in a head-to-tail manner. Saci_0406 displays structural similarity, but low sequence homology, to bacterial type-I pilins. Thread subunits are interconnected via donor strand complementation, a feature reminiscent of bacterial chaperone-usher pili. However, despite these similarities in overall architecture, archaeal threads appear to have evolved independently and are likely assembled by a distinct mechanism.
Keyphrases
- biofilm formation
- pseudomonas aeruginosa
- staphylococcus aureus
- candida albicans
- escherichia coli
- single cell
- high resolution
- cell therapy
- single molecule
- machine learning
- gene expression
- stem cells
- deep learning
- cystic fibrosis
- mesenchymal stem cells
- circulating tumor
- oxidative stress
- genome wide
- copy number
- bone marrow
- cell free
- high speed
- transcription factor
- endoplasmic reticulum
- cell adhesion