Structure, enzymatic function and RNA-binding of ribosome assembly factor Nep1

Nep1 is an essential factor for the ribosome biogenesis in eukaryotes. A mutation in the human Nep1 is the cause of the Bowen-Conradi syndrome, one of the heavy developmental disorder, which is mortal already in the infancy. Our structure determination and subsequent NMR-based enzymatic assays show that Nep1 is a pseudouridine-specific N3-methyltransferase, which introduces a specific modification in the 18S ribosomal RNA. By solution NMR the RNA-binding site of Nep1 was identified and the RNA-specificity of Nep1 was analysed. The mutation responsible for the Bowen-Conradi syndrome is located in this RNA-binding site.


  • Taylor, A. B., Meyer, B., Leal, B. Z., Köttter, P., Schirf, V., Demeler, B., Hart, P. J., Entian, K. D. & Wöhnert, J. The crystal structure of Nep1 reveals an extended SPOUT-class methyltransferase fold and a pre-organized SAM-binding site. Nucl. Acids Res. 36, 1542-1554 (2008)