Properties of a HeLa cell 3' exonuclease specific for degrading poly(A) tails of mammalian mRNA.
A HeLa cell 3'-exonuclease with properties of a mammalian mRNA poly(A) tail-removing enzyme has been characterized. The exonuclease shows high specificity for the poly(A) tail, and it is single strand-specific and requires a 3'-hydroxyl group for its activity. During degradation 5'-AMP is liberated as a product, and a 3'-OH group is left on the last adenosine residue of the remaining poly(A) tail. The activity is inhibited by 5'-AMP and can be competed by poly(A)-containing mRNA or poly(A). Based on these findings we propose a reaction pathway for poly(A) tail removal catalyzed by the HeLa cell poly(A) tail-specific 3' exonuclease.
Department of Medical Genetics, Uppsala University, Sweden.
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Aström
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Aström
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Virtanen
D001483:Base Sequence; D002482:Cellulose / Q000031:analogs & derivatives; D002845:Chromatography; D002846:Chromatography, Affinity; D002852:Chromatography, Ion Exchange; D002855:Chromatography, Thin Layer; D004591:Electrophoresis, Polyacrylamide Gel; D005092:Exonucleases / Q000302:isolation & purification / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D011061:Poly A / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism*; D012260:Ribonucleases; D013379:Substrate Specificity
D012333:RNA, Messenger; D011061:Poly A; D002482:Cellulose; C008881:phosphocellulose; D005092:Exonucleases; D012260:Ribonucleases; C022650:spleen exonuclease