Poly(U)-binding protein inhibits Drosophila pre-5 S RNA 3'-exonuclease digestion.
A approximately 50-kDa protein binds specifically to the 3' terminus of 135-nucleotide Drosophila pre-5 S RNA. Unlabeled poly(U) competes out protein binding and stimulates the activity of a 3'-exonuclease, which eventually degrades the substrate to 120 nucleotides, the size of mature 5 S RNA. In its RNA binding and UV cross-linking properties, the endogenous poly(U)-binding protein resembles human La, an autoantigen that binds the U > 3 3' ends of vertebrate RNA polymerase III primary transcripts. This protein appears to inhibit a 3' exonuclease and could protect 5 S RNA for faithful processing and transport.
School of Life and Health Sciences, University of Delaware, Newark 19716.
P
P
Preiser
V
V
Vasisht
A
A
Birk
L
L
Levinger
D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D002460:Cell Line; D004331:Drosophila melanogaster / Q000378:metabolism*; D005092:Exonucleases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D007700:Kinetics; D012320:RNA Polymerase III / Q000378:metabolism; D012322:RNA Precursors / Q000378:metabolism*; D012323:RNA Processing, Post-Transcriptional; D012341:RNA, Ribosomal, 5S / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism; D014158:Transcription, Genetic
D002352:Carrier Proteins; D012322:RNA Precursors; D012341:RNA, Ribosomal, 5S; D016601:RNA-Binding Proteins; D012320:RNA Polymerase III; D005092:Exonucleases