A 64 kd nuclear protein binds to RNA segments that include the AAUAAA polyadenylation motif.
A 64 kd protein was shown to bind to RNAs that contain functional polyadenylation signals by a UV cross-linking procedure in which label was transferred from RNA substrate to protein in cell-free polyadenylation extracts. The 64 kd nuclear protein bound specifically to three different substrates (adenovirus type 5 L3, SV40 early, and SV40 late polyadenylation domains), as determined by competition experiments and partial protease analysis. Deleted derivatives of the SV40 late substrate that retained the sequence 5'-CUGCAAUAAACAAGUU-3' were able to bind the 64 kd polypeptide. This sequence contains the canonical AAUAAA element that has been shown to be indispensable for polyadenylation. A single nucleotide change, converting AAUAAA to AAGAAA, prevented binding of the 64 kd moiety. The 64 kd protein was shown to be distinct from poly(A) polymerase by biochemical fractionation.
Wilusz
J
J
Department of Molecular Biology, Princeton University, New Jersey 08544.
Shenk
T
T
D000256:Adenoviridae / Q000235:genetics*; D001483:Base Sequence; D001665:Binding Sites; D001667:Binding, Competitive; D004591:Electrophoresis, Polyacrylamide Gel; D008970:Molecular Weight; D009154:Mutation; D009687:Nuclear Proteins / Q000378:metabolism*; D010777:Photochemistry; D011061:Poly A / Q000378:metabolism*; D011062:Polynucleotide Adenylyltransferase / Q000378:metabolism; D012367:RNA, Viral / Q000378:metabolism*; D013539:Simian virus 40 / Q000235:genetics*; D013698:Templates, Genetic
D009687:Nuclear Proteins; D012367:RNA, Viral; D011061:Poly A; D011062:Polynucleotide Adenylyltransferase