8 Poly(A) Adding Enzymes

摘要: Publisher Summary This chapter discusses the multiplicity, cellular localization, and regulation of poly(A) adding enzymes. It illustrates poly (A) reactions that are restricted to enzymes attach adenosine monophosphate (AMP) residues from triphosphate (ATP) 3′ end polyribonucleotides through 3′- 5′-phosphodiester bonds. These show a high specificity for ATP low primer. Most purified polymerases is able use variety oligoribonucleotides differing in sequence length as primers. Poly(A) present all living organisms because sequences apparently ubiquitous. Purifications have been reported viruses, bacteria, yeasts, plant animal tissues, cultured cells. The most highly preparations calf thymus, rat liver nuclei, HeLa cells, E. coli provided basic information defines reaction vitro . Activities might interfere with polymerase assay, such RNA polymerase, tRNA nucleotidyltransferase, polynucleotide phosphorylase, ATPases, removed at early stages purification since they not detected tissues.