Pertactin, central region (IPR004899)

Short name: Pertactin_central

Overlapping homologous superfamilies

Domain relationships



Bordetella pertussis is a Gram-negative, aerobic coccobacillus that causes pertussis (whooping cough), especially in young children [PMID: 2542937]. Once present in the lungs, the bacterium attaches to ciliated pulmonary epithelial cells via a collection of outer membrane proteins, all of which are virulence factors.

Pertactin, or P69 protein, is one of these virulence factors. Pertactin and filamentous haemagglutinin have been identified as Bordetella adhesins [PMID: 1527510]. Both proteins contain an arg-gly-asp (RGD) motif that promotes binding to integrins, known to be important in cell mobility and development. The production of most Bordetella virulence factors (including pertactin) is controlled by a two-component signal transduction system, comprising the BvgA regulator and the BvgS sensor [PMID: 10943406]. Pertactin shares a high level of similarity with other Bordetella adhesins, such as BrkA. The protein is first produced as a 93kDa precursor. Upon secretion into the extracellular environment, a 30kDa domain at the C terminus remains in the outer membrane, while the mature 60.4kDa pertactin molecule is released [PMID: 8609998].

The crystal structure of mature pertactin has been determined to 2.5A resolution by means of X-ray diffraction. The fold is characterised by a 16-stranded parallel beta-helix, with a V-shaped cross-section. Several between-strand amino-acid repeats form internal and external ladders. The helical structure is interrupted by several protruding loops that contain motifs associated with the activity of the protein. One such sequence - [GGXXP]5 - appears directly after the RGD motif, and may mediate interaction with epithelial cells. The C-terminal region of P.69 pertactin contains a [PQP]5 motif loop, which contains the major immunoprotective epitope [PMID: 8609998].

The superfamily also includes immunoglobulin A1 protease and adhesion penetration protein HAP.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.