Utp13 is a component of the five protein Pwp2 complex that forms part of a stable particle subunit independent of the U3 small nucleolar ribonucleoprotein that is essential for the initial assembly steps of the 90S pre-ribosome [1]. Pwp2 is capable of interacting directly with the 35 S pre-rRNA 5' end [1].

1: Functional characterization of Pwp2, a WD family protein essential for the assembly of the 90 S pre-ribosomal particle. Dosil M, Bustelo XR; J Biol Chem. 2004;279:37385-37397. PMID:15231838