5-445: PNPase can refer to: Polynucleotide phosphorylase , an RNA degrading protein Purine nucleoside phosphorylase , an enzyme involved in purine metabolism Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with the title PNPase . If an internal link led you here, you may wish to change
10-454: Is a bifunctional enzyme with a phosphorolytic 3' to 5' exoribonuclease activity and a 3'-terminal oligonucleotide polymerase activity. That is, it dismantles the RNA chain starting at the 3' end and working toward the 5' end. It also synthesizes long, highly heteropolymeric tails in vivo . It accounts for all of the observed residual polyadenylation in strains of Escherichia coli missing
15-485: Is encoded by the PNPT1 gene. In its active form, the protein forms a ring structure consisting of three PNPase molecules. Each PNPase molecule consists of two RNase PH domains, an S1 RNA binding domain and a K-homology domain . The protein is present in bacteria and in the chloroplasts and mitochondria of some eukaryotic cells. In eukaryotes and archaea , a structurally and evolutionary related complex exists, called
20-417: The link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=PNPase&oldid=933058984 " Category : Disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages Polynucleotide phosphorylase Polynucleotide Phosphorylase ( PNPase )
25-524: The normal polyadenylation enzyme. Discovered by Marianne Grunberg-Manago working in Severo Ochoa 's lab in 1955, the RNA-polymerization activity of PNPase was initially believed to be responsible for DNA-dependent synthesis of messenger RNA, a notion that was disproven by the late 1950s. It is involved in mRNA processing and degradation in bacteria, plants, and animals. In humans, the enzyme
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