PXD066463-1

PXD066463 is an original dataset announced via ProteomeXchange.

Title	Structural remodeling of flagellar filament drives biofilm formation in oral pathogen Treponema denticola
Description	Biofilms are structured microbial communities that underlie many chronic infections, including periodontal disease. Their resilience to antimicrobial treatments and immune responses presents major clinical challenges. Yet, the structural changes bacteria undergo during biofilm formation and the structural basis of cell-cell interactions within biofilms remain poorly defined. Treponema denticola, a key oral spirochete and periodontal pathogen, forms complex biofilms at disease sites in the oral cavity. Here, combining confocal laser scanning microscopy with fluorescence in situ hybridization (CLSM-FISH) and cryo-electron tomography (cryo-ET), we show that spiral-shaped planktonic cells undergo profound morphological transitions to form densely packed, intertwined cell-clusters often with distinct yarn- or braid-like architectures. Remarkably, we observed frequent lateral cell fusions within biofilms, suggesting a novel mechanism for maintaining homeostasis. Our cryo-ET data unraveled that T. denticola structurally remodels its periplasmic flagella during biofilm formation and maturation. Combining cryo-ET and sub-tomogram averaging, we resolved two distinct flagellar assemblies within biofilms at <9.0 Å. Further single particle analysis refined these to near-atomic resolution (<3.0 Å), resulting in complete atomic models of distinct flagellar conformations. In Td flagellum, we identified two previously uncharacterized proteins, conserved across the Treponema genus, which contribute to the complex asymmetric lattice comprising seven different components. Together, these findings uncovered novel architectural features of T. denticola biofilms and revealed how structural plasticity of the motility machinery facilitates stable community formation. This work highlights a previously unappreciated link between flagellar structure and biofilm development, potentially conserved across other pathogenic bacteria.
HostingRepository	PRIDE
AnnounceDate	2026-08-25
AnnouncementXML	Submission_2026-08-24_23:45:38.764.xml
DigitalObjectIdentifier
ReviewLevel	Peer-reviewed dataset
DatasetOrigin	Original dataset
RepositorySupport	Unsupported dataset by repository
PrimarySubmitter	Paul Veith
SpeciesList	scientific name: Treponema denticola ATCC 35405; NCBI TaxID: NEWT:243275;
ModificationList	monohydroxylated residue; iodoacetamide derivatized residue
Instrument	LTQ Orbitrap

Revision	Datetime	Status	ChangeLog Entry
0	2025-07-23 04:26:55	ID requested
⏵ 1	2026-08-24 23:45:39	announced

Dataset with its publication pending

submitter keyword: In situ structural Biology, Cryo-electron tomography, Biofilm, Cryo-EM Single Particle Analysis, Oral pathogen, Bacterial flagella

Debnath Ghosal
contact affiliation	Department of Biochemistry and Pharmacology, University of Melbourne, Victoria, Australia
contact email	debnath.ghosal@unimelb.edu.au
lab head
Paul Veith
contact affiliation	Melbourne Dental School
contact email	pdv@unimelb.edu.au
dataset submitter

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PRIDE project URI

• PRIDE
  1. PXD066463
     1. Label: PRIDE project
     2. Name: Structural remodeling of flagellar filament drives biofilm formation in oral pathogen Treponema denticola