Analysis of polyadenylate . protein complex of polysomal messenger RNA from mouse L cells.
The organization of polysomal poly(A)-ribonucleoprotein complex [poly(A)-RNP] was studied. The poly(A)-associated proteins were liberated directly from the poly(A)-RNP complex. Polysomal mRNA was isolated from L5178y mouse lymphoma cells by oligo (dT)-cellulose chromatography; poly(A)-RNP was prepared by nuclease digestion. The poly(A)-RNP fraction was considered to be pure basing on the size of its poly(A) component which was determined to consist of 155 AMP moieties. By radiolabeling with [3H]dansyl chloride, two poly(A)-associated proteins with molecular masses of 77,000 Da (P77) and 54,000 Da (P54) were identified. In a quantitative approach, it was shown that the polysomal poly(A)-RNP complex is composed of approximately 4 molecules P54 and 2 molecules P77. Digestion experiments with dimers and tetramers containing ribonuclease A indicated that P54 covers 15-20 AMP residues and P77 a sequence of 40-45 ribonucleotides on the poly(A)--155 stretch of polysomal poly(A)-RNP.
D000818:Animals; D007739:L Cells / Q000032:analysis; D051379:Mice; D008970:Molecular Weight; D009698:Nucleoproteins / Q000032:analysis*; D011061:Poly A / Q000032:analysis*; D011132:Polyribosomes / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis*; D012261:Ribonucleoproteins / Q000032:analysis*; D012269:Ribosomal Proteins / Q000032:analysis*
D009698:Nucleoproteins; D012333:RNA, Messenger; D012261:Ribonucleoproteins; D012269:Ribosomal Proteins; D011061:Poly A