Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.3.5 (5'-nucleotidase)
 3,167 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A procedure for the quantitative measurement of the O2'-methylnucleoside constitutents of RNA has recently been developed in this laboratory (Gray, M.W. Can. J. Biochem. 53, 735-746 (1975)). This assay method is based on the resistance of O2'-methylnucleoside 5'-phosphates (pNm) (generated by phosphodiesterase hydrolysis of RNA) to subsequent dephosphorylation by venom 5'-nucleotidase (EC 3.1.3.5). In the present investigation, two base-modified 5'-nucleotides, each displaying an unusual resistance to 5'-nucleotidase, have been identified. These compounds have been characterized by a variety of techniques as N2, N2-dimethylguanosine 5'-phosphate (pm2/2G) and 3-(3-amino-3-carboxypropyl)uridine 5'-phosphate (p4abu3U). Because of their resistance to 5'-nucleotidase, pm2/2G and p4abu3U are isolated along with the pNm in the mononucleotide fraction of venom hydrolysates of transfer RNA. Under hydrolysis conditions, the stability of p4abu3U is comparable to that of a pNm, allowing quantitative assay of the nucleotide. The proportion (mean +/- SD) of p4abu3U in venom hydrolysates of wheat embryo and Escherichia coli tRNA has been determined to be 0.35 +/- 0.03 (n=5) and 0.14 +/- 0.02 (n=4) mol%, respectively. The absence of p4abu3U in venom hydrolysates of yeast tRNA implies the absence of the corresponding nucleoside in yeast tRNA, in agreement with existing data. The variable recovery of pm2/2G from venom hydrolysates of wheat embryo and yeast tRNA indicates that under hydrolysis conditions, this base-modified nucleotide is only partially resistent to 5'-nucleotidase. The complete absence of pm2/2G in venom hydrolysates of E. coli tRNA is consistent with the known absence of N2, N2-dimethylguanosine in this RNA. These observations demonstrate that resistance to 5'-nucleotidase is a necessary but not sufficient criterion for concluding that a 5'-nucleotide is O2'-methylated. When applied to wheat embryo ribosomal RNA, the analytical methods described in this report failed to reveal any compound having the distinctive charge properties of p4abu3U. It therefore appears that 1-methyl-3-(3-amino-3-carboxypropyl)pseudouridine, recently characterized as a constituent of the 18 S rRNA of Chinese hamster cells (Saponara, A.G. & Enger, M.D. Biochim. Biophys. Acta 349, 61-77 (1974)), may not be present in wheat embryo ribosomal RNA.
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PMID:Modified 5'-nucleotides resistant to 5'-nucleotidase: isolation of 3-(3-amino-3-carboxypropyl) uridine 5'-phosphate and N2, N2-dimethylguanosine 5'-phosphate from snake venom hydrolysates of transfer RNA. 0 33

The incorporation of the cytokinin N(6)-benzyladenine into tobacco (Nicotiana tabacum) callus tRNA and rRNA preparations isolated from tissue grown on medium containing either N(6)-benzyladenine-8-(14)C or N(6)-benzyladenine-8-(14)C: benzene-(3)H(G) has been examined. N(6)-benzyladenine was incorporated into both the tRNA and rRNA preparations as the intact base. Over 90% of the radioactive N(6)-benzyladenosine recovered from the RNA preparations was associated with the rRNA. Purification of the crude rRNA by either MAK chromatography or Sephadex G-200 gel filtration had no effect on the N(6)-benzyladenosine content of the RNA preparation. The distribution of N(6)-benzyladenosine moieties in tobacco callus tRNA fractionated by BD-cellulose chromatography did not correspond to the distribution of ribosylzeatin activity. N(6)-benzyladenosine was released from the rRNA preparation by treatment with venom phosphodiesterase and phosphatase, ribonuclease T(2) and phosphatase, or ribonuclease T(2) and a 3'-nucleotidase. N(6)-benzyladenosine was not released from the RNA preparation by treatment with either ribonuclease T(2) or phosphatase alone or by successive treatment with ribonuclease T(2) and a 5'-nucleotidase. Brief treatment of the rRNA preparation with ribonuclease T(1) and pancreatic ribonuclease converted the N(6)-benzyladenosine moieties into an ethyl alcohol soluble form. On the basis of these and earlier results, the N(6)-benzyladenosine recovered from the tobacco callus RNA preparations appears to be present as a constituent of RNA and not as a nonpolynucleotide contaminant.
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PMID:Incorporation of cytokinin N-benzyladenine into tobacco callus transfer ribonucleic Acid and ribosomal ribonucleic Acid preparations. 1665 17