DBP45A ENCODES A DROSOPHILA DEAD BOX PROTEIN WITH SIMILARITY TO A PUTATIVE YEAST HELICASE INVOLVED IN RIBOSOME ASSEMBLY

Proteins of the DEAD family of putative ATP-dependent RNA helicases ha ve been implicated in translation initiation, ribosome assembly, and R NA processing in a variety of organisms from Escherichia coli to man. Among these proteins are eIF-4A, an essential component of the cap-bin ding complex, numerous yeast proteins required for pre-mRNA splicing, and proteins from yeast and E. coli necessary for ribosome assembly. W e report the isolation of a new DEAD gene from Drosophila, Dbp45A, whi ch is most abundantly expressed in 6-12 h embryos and adults. The pred icted amino acid sequence of the Dbp45A product contains all eight hig hly conserved DEAD family motifs, and most closely resembles the Sacch aromyces cerevisiae DRS1p among known DEAD box proteins. DRS1p has bee n implicated in ribosomal RNA processing.