Retinoblastoma protein–Adenovirus Early Region 1A Conserved Region 2 interface (RB1–E1A CR2)

The Retinoblastoma protein (pRb)–Adenovirus E1A CR2 interface is a critical protein-protein interaction site involved in cell cycle control and viral pathogenesis (UniProt P06400, P03372). pRb normally functions as a tumor suppressor by sequestering E2F transcription factors, thereby preventing premature entry into the S-phase. The Adenovirus E1A protein, specifically through its Conserved Region 2 (CR2) domain containing the LXCXE motif, binds to the B-box of the pRb pocket domain (Lee et al., 1998, Nature 391:859-865). This binding competitively displaces E2F, leading to uncontrolled cell proliferation and facilitating viral replication (Dick, 2007, Cell Division 2:7). Targeting this interface with small molecules or peptidomimetics aims to prevent viral subversion of the host cell cycle or to restore pRb's tumor-suppressive function in contexts where it is inhibited by viral oncoproteins. This interface is a prototype for interactions between pRb and various other viral (e.g., HPV E7, SV40 Large T antigen) and cellular proteins. Research into this target has led to the development of LXCXE-mimetic peptides and small molecules designed to disrupt the interaction (Singh et al., 2005, Bioorg Med Chem Lett 15:2579-2582). Understanding the structural basis of this interface is essential for designing selective inhibitors that do not interfere with other essential pRb functions.

Other names

pRb-E1A interactionRB1-E1A complexLXCXE-binding pocket of pRbRetinoblastoma protein-Adenovirus Early Region 1A interface

Inhibition of protein-protein interaction (PPI) between pRb and the LXCXE motif of E1A