Ebp2p, the yeast homolog of Epstein-Barr virus nuclear antigen 1-binding protein 2, interacts with factors of both the 60 S and the 40 S ribosomal subunit assembly

Ebp2p, the yeast homolog of human Epstein-Barr virus nuclear antigen 1-binding protein 2, is essential for biogenesis of the 60 S ribosomal subunit. Two-hybrid screening exhibited that, in addition to factors necessary for assembly of the 60 S subunit, Ebp2p interacts with Rps16p, ribosomal protein S16, and the 40 S ribosomal subunit assembly factor, Utp11p, as well as Yil019w, the function of which was previously uncharacterized. Depletion of Yil019w resulted in reduction in levels of both of 18 S rRNA and 40 S ribosomal subunit without affecting levels of 25 S rRNA and 60 S ribosomal subunits. 35 S pre-rRNA and aberrant 23 S RNA accumulated, indicating that pre-rRNA processing at sites A(0)-A(2) is inhibited when Yil019w is depleted. Each combination from Yil019w, Utp11p, and Rps16p showed two-hybrid interaction.