D. Kressler et al., DBP6P IS AN ESSENTIAL PUTATIVE ATP-DEPENDENT RNA HELICASE REQUIRED FOR SOS-RIBOSOMAL-SUBUNIT ASSEMBLY IN SACCHAROMYCES-CEREVISIAE, Molecular and cellular biology, 18(4), 1998, pp. 1855-1865
A previously uncharacterized Saccharomyces cerevisiae open reading fra
me, YNR038W, was analyzed in the context of the European Functional An
alysis Network. YNR038W encodes a putative ATP-dependent RNA helicase
of the DEAD-box protein family and was therefore named DBP6 (DEAD-box
protein 6). Dbp6p is essential for cell viability. In vivo depletion o
f Dbp6p results in a deficit in 60S ribosomal subunits and the appeara
nce of half-mer polysomes. Pulse-chase labeling of pre-rRNA and steady
-state analysis of pre-rRNA and mature rRNA by Northern hybridization
and primer extension show that Dbp6p depletion leads to decreased prod
uction of the 27S and 7S precursors, resulting In a depletion ok the m
ature 25S and 5.8S rRNAs. Furthermore, hemagglutinin epitope-tagged Db
p6p is detected exclusively within the nucleolus. We propose that Dbp6
p is required for the proper assembly of preribosomal particles during
the biogenesis of 60S ribosomal subunits, probably by acting as an rR
NA helicase.