InterPro: IPR000931 Adenovirus fibre protein

Adenoviruses are responsible for diseases such as pneumonia, cystitis, conjunctivitis and diarrhoea, all of which can be fatal to patients who are immunocompromised [1]. Viral infection commences with recognition of host cell receptors by means of specialised proteins on viral surfaces. The adenovirus fibre protein `knob domain' at the C terminus is one such receptor-binding protein subunit. The crystal structure of the knob domain reveals a trimeric organisation, each subdomain folded into 2 functionally distinct beta-sheets. The V sheet is highly conserved, and provides contact surfaces in the formation of the trimer, while the R sheet is more variable, and may play a role in viral-receptor interactions. The overall shape of the trimer resembles a 3-bladed propeller, with a central surface depression and 3 valleys formed by the symmetry-related R sheets. Sequence comparison of different types of adenovirus fibre protein suggests an overall similarity in the structure of the knob domain. The main conserved regions lie in the central surface depression around the 3-fold symmetry axis [1]. The N terminus of the protein contains the 'shaft' region.