PG1058 Is a Novel Multidomain Protein Component of the Bacterial Type IX Secretion System.

Porphyromonas gingivalis utilises the Bacteroidetes-specific type IX secretion system (T9SS) to export proteins across the outer membrane (OM), including virulence factors such as the gingipains. The secreted proteins have a conserved carboxy-terminal domain essential for type IX secretion that is cleaved upon export. In P.

Porphyromonas gingivalis and Treponema denticola exhibit metabolic symbioses.

Porphyromonas gingivalis and Treponema denticola are strongly associated with chronic periodontitis. These bacteria have been co-localized in subgingival plaque and demonstrated to exhibit symbiosis in growth in vitro and synergistic virulence upon co-infection in animal models of disease. Here we show that during continuous co-culture a P.

C-terminal domain residues important for secretion and attachment of RgpB in Porphyromonas gingivalis.

Porphyromonas gingivalis, a periodontal pathogen, expresses a group of surface proteins with a common C-terminal domain (CTD) that are exported by a novel secretion system to the surface, where they are covalently attached. Using RgpB as a model CTD protein, we have produced a series of site-directed mutations in the CTD sequence at conserved residues and at residues that may be modified and, hence, surface attached. The mutant RgpB proteins were expressed in a P.

Treponema denticola biofilm-induced expression of a bacteriophage, toxin-antitoxin systems and transposases.

Treponema denticola is an oral spirochaete that has been strongly associated with chronic periodontitis. The bacterium exists as part of a dense biofilm (subgingival dental plaque) accreted to the tooth. To determine T.