A protein complex that assists early maturation of nascent 60S ribosomal subunits. The complex interacts with the large ribosomal subunit rRNA via one of the components (Urb2 in S. cerevisiae) and requires a RNA helicase (Dbp6 in S. cerevisiae).
Source:
GOC:lnp,
PMID:17145778,
PMID:9528757