Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.8 (polynucleotide phosphorylase)
 723 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The infectivity of replicative form RNA (RF-RNA) isolated from poliovirus-infected HeLa cells is completely resistant to the action of T-1 RNase but decreases after exposure to RNase A in the presence of 0.3 M NaCl. Under these conditions neither enzyme produces single-stranded nicks in RF-RNA. Three endonuclease-free exonuleases (RNase II, polynucleotide phosphorylase and spleen phosphodiesterase) rapidly destroy the infectivity of single-stranded RNA, but do not alter the infectivity of RF-RNA. It is concluded that RF-RNA does not contain single-stranded ends essential for infectivity. Indirect evidence suggests that all or most of the poly A region at the 3' end of the plus strand of infectious RF-RNA is base-paired to a poly U region at the 5 end of the minus strand.
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PMID:Poliovirus-induced infectious double-stranded RNA: Effect of RNA-degrading enzymes. 16 28

We describe a method for obtaining radioactive fingerprints from nonradioactive ribonucleic acid. Fragments derived by T1 ribonuclease digestion of RNA are dephosphorylated with bacterial alkaline phosphatase. When these fragments are used as primers for the reaction of primer dependent polynucleotide phosphorylase with [alpha-(32)P]GDP in the presence of T1 ribonuclease the 3'-hydroxyl group of each fragment becomes phosphorylated. The degree of phosphorylation is reasonably uniform. The method has been applied to T1 ribonuclease digests of Escherichia coli tRNA(Met) (f); the oligonucleotides were further analyzed by spleen phosphodiesterase digestion. In a similar manner fingerprints of pancreatic ribonuclease digests of RNA can be obtained, when [alpha-(32)P]UDP, polynucleotide phosphorylase and pancreatic ribonuclease are used.
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PMID:Fingerprinting nonradioactive ribonucleic acid with the aid of polynucleotide phosphorylase. 1079 69

In a continuing effort to identify ribonucleases that may be involved in mRNA decay in Bacillus subtilis, fractionation of a protein extract from a triple-mutant strain that was missing three previously characterized 3'-to-5' exoribonucleases (polynucleotide phosphorylase [PNPase], RNase R, and YhaM) was undertaken. These experiments revealed the presence of a high-molecular-weight nuclease encoded by the yhcR gene that was active in the presence of Ca(2+) and Mn(2+). YhcR is a sugar-nonspecific nuclease that cleaves endonucleolytically to yield nucleotide 3'-monophosphate products, similar to the well-characterized micrococcal nuclease of Staphylococcus aureus. YhcR appears to be located principally in the cell wall and is likely to be a substrate for a B. subtilis sortase. Zymogram analysis suggests that YhcR is the major Ca(2+)-activated nuclease of B. subtilis. In addition to having a unique overall domain structure, YhcR contains a hitherto unknown structural domain that we have named "NYD," for "new YhcR domain."
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PMID:Bacillus subtilis YhcR, a high-molecular-weight, nonspecific endonuclease with a unique domain structure. 1529 38

The reaction of polyuridylic acid with sodium bisulfite produces modified polymers in which up to 95% of the uracil residues have been converted to uracil-6-sulfonate residues. A 91.6% bisulfite-saturated polymer was found to resist hydrolysis by spleen phosphodiesterase and phosphorolysis by polynucleotide phosphorylase. Digestion by pancreatic ribonuclease was successful and gave the bisulfite adduct of uridine-3'-phosphate. Treatment of this nucleotide adduct with acid phosphatase afforded the bisulfite adduct of uridine. The ability of polyuridylic acid to bind to ribosomes, and to stimulate the binding of phenylalanine tRNA to ribosomes was abolished by progressive bisulfite saturation of the polymer. The rate of decline of these functionsf with increasing bisulfite content, was less sharp than the loss of phenyl-alanine coding ability o, the modified polymer.
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PMID:Modification of polyuridylic acid by bisulfite. II: Studies on ribosomal binding and enzymatic hydrolysis. 2419 77