Polypyrimidine tract-binding protein stimulates the poliovirus IRES by modulating eIF4G binding.

ABSTRACT: Tethered hydroxyl-radical probing has been used to determine the orientation of binding of polypyrimidine tract-binding protein (PTB) to the poliovirus type 1 (Mahoney) (PV-1(M)) internal ribosome entry site/segment (IRES)-the question of which RNA-binding domain (RBD) binds to which sites on the IRES. The results show that under conditions in which PTB strongly stimulates IRES activity, a single PTB is binding to the IRES, a finding which was confirmed by mass spectrometry of PTB/IRES complexes. RBDs1 and 2 interact with the basal part of the Domain V irregular stem loop, very close to the binding site of eIF4G, and RBDs3 and 4 interact with the single-stranded regions flanking Domain V. The binding of PTB is subtly altered in the presence of the central domain (p50) of eIF4G, and p50 bin

SUBMITTER: Kafasla P 

PROVIDER: S-EPMC2982756 | biostudies-literature | 2010 Nov

REPOSITORIES: biostudies-literature