# Structural basis of host recognition and biofilm formation bySaf pili.
> Safピリの宿主認識とバイオフィルム形成における構造的基盤


## Abstract

This study investigated the structural basis of Saf pili, which play key roles in bacterial infection processes including host recognition and biofilm formation. Crystal structures of SafD and the SafDAA complex were determined, and cell adherence assays demonstrated that both SafD and SafA contribute to host recognition, indicating a poly-adhesive mechanism. SAXS characterization of the SafDAA complex revealed intermolecular oligomerization, leading to examination of Saf-driven self-association in biofilm contexts. Bead and cell aggregation assays confirmed this novel self-associating function. Structure-guided mutations disrupting intermolecular hydrogen bonds within SafDAA dimers substantially reduced self-association activity and biofilm formation. These findings define two previously unrecognized functions of Saf pili—poly-adhesive and self-associating activities—and establish a pili-mediated intercellular oligomerization mechanism relevant to bacterial aggregation and colonization.

### Mechanism

Intermolecular hydrogen bonds within SafDAA dimers drive bacterial self-association, enabling pili-mediated intercellular oligomerization that promotes aggregation and biofilm formation.

## Bibliographic

- **Authors**: Zeng L, Zhang LL, Wang P, Meng G
- **Journal**: Elife
- **Year**: 2017 (2017-11-10)
- **PMID**: [29125121](https://pubmed.ncbi.nlm.nih.gov/29125121/)
- **DOI**: [10.7554/eLife.28619](https://doi.org/10.7554/eLife.28619)
- **PMC**: [PMC5700814](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5700814/)
- **Study type**: other
- **Delivery route**: not specified
- **Effect reported**: not assessed

## Delivery context

The delivery route is not clearly identifiable from this paper. For hydrogen intake, inhalation is the most efficient route; inhalation, however, carries explosion risk (empirical LFL of 10%; high-concentration devices are not recommended).

## Safety notes

The delivery route is not clearly identifiable from this paper. For hydrogen intake, inhalation is the most efficient route; inhalation, however, carries explosion risk (empirical LFL of 10%; high-concentration devices are not recommended).

See also:
- [Inhalation concentration and LFL / UFL](https://h2-papers.org/en/safety-notes/inhalation-concentration)
- [Consumer Affairs Agency accident cases](https://h2-papers.org/en/safety-notes/accident-cases)

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> **Cite as**: H2 Papers — PMID 29125121. https://h2-papers.org/en/papers/29125121
> **Source**: PubMed PMID [29125121](https://pubmed.ncbi.nlm.nih.gov/29125121/)