Functional analysis of human papillomavirus type 16 E7 by complementation with adenovirus E1A mutants.

Functional analysis of human papillomavirus type 16 E7 protein by complementation with adenovirus E1A mutants in baby rat kidney cells has shown that the retinoblastoma gene product (RB)-binding region of E7 can substitute in trans for that of E1A. An N-terminal E7 mutant was unable to complement an E1A mutant unable to bind p300, indicating that the two mutants were defective for functionally equivalent activities. E7 proteins with mutations within the RB-binding region were also unable to complement either the non-p300-binding E1A mutant or the N-terminal E7 mutant, suggesting that these mutations affect more than just RB binding.