Structural determinants within the adenovirus early region 1A protein spacer region necessary for tumourigenesis.

It has long been established that group-A adenoviruses (HAdV-A12, -A18 and -A31) can cause tumours in new-born rodents with tumourigenicity related to the presence of a unique spacer region located between conserved regions 2 and 3 within the Ad12E1A protein.  Group B adenoviruses are weakly oncogenic whereas most of the remaining human adenoviruses are non-oncogenic. In order to understand better the relationship between the structure of the AdE1A spacer region and oncogenicity of HAdVs the structure of synthetic peptides identical or very similar to the adenovirus12 E1A spacer region have been determined to be α-helical using NMR spectroscopy. This contrasts significantly with some previous suggestions that this region is unstructured. Using available predictive algorithms, the structures of spacer regions from other E1As were also examined and the extent of predicted α-helix was found to correlate reasonably well with the tumorigenicity of the respective viruses.