Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.27.3 (RNase T1)
 1,228 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A method is described to classify, in regard to their location within the genome, fragments obtained by partial cleavage of 32P-labeled bacteriophage Qbeta RNA. The location of many fragments suitable for sequence analysis could be established using as markers 29 large RNase T1-resistant oligonucleotides with known map positions. Applying this method four fragments originating from the coat protein cistron were isolated and analyzed. The sequence of a segment of 239 nucleotides located immediately adjacent to the initiation triplet was determined to be G-C-A-A-A-A-U-U-A-G-A-G-A-C-U-G-U-U-A-C-U-U-U-A-G-G-U-A-A-C-A-U-C-G-G-G-A-A-A-G-A-U-G-G-A-A-A-A-C-A-A-A-C-U-C-U-G-G-U-C-C-U-C-A-A-U-C-C-G-C-G-U-G-G-G-G-U-A-A-A-U-C-C-C-A-C-U-A-A-C-G-G-C-G-U-U-G-C-C-U-C-G-C-U-U-U-C-A-C-A-A-G-C-G-G-G-U-G-C-A-G-U-U-C-C-U-G-C-G-C-U-G-G-A-G-A-A-G-C-G-U-G-U-U-A-C-C-G-U-U-U-C-G-G-U-A-U-C-U-C-A-G-C-C-U-U-C-U-C-G-C-A-A-U-C-G-U-A-A-G-A-A-C-U-A-C-A-A-G-G-U-C-C-A-G-G-U-U-A-A-G-A-U-C-C-A-G-A-A-C-C-C-G-A-C-C-G-C-U-U-G-C-A-C-U-G-C-A-A-A-C-G-G-U-U-C-U-U-Gp. The primary structure and the secondary structure model derived from it did not provide any evidence of homology with the corresponding RNA region of bacteriophage MS2.
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PMID:Determination of the first half of the coat protein cistron of bacteriophage Qbeta as an application of a mapping procedure for RNA fragments. 36 41

Four large MS2 RNA fragments with the original 5'-end were obtained by limited RNase T1 digestion. The lengths of the fragments were 36, 30, 22, and 19% of the whole molecule. Whole MS2 RNA and the four fragments were completely digested with RNase T1 and analyzed by the two-dimensional "homochromatography fingerprint" technique. Sixteen oligonucleotides of MS2 RNA were separated and the oligonucleotides were assigned to the fragments. Fifteen of the sixteen oligonucleotides could be classified into three regions of the cistrons of bacteriophage MS2.
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PMID:Allocation of 15 RNase T1-resistant large oligonucleotides of MS2 RNA. 77 61

32P-Labeled MS2 RNA was partially digested with ribonuclease T1 (guanyloribonuclease; ribonucleate 3'-guanylo-oligonucleotidohydrolase; EC 3.1.4.8) or with epilson-carboxymethyl-lysine-41 pancreatic ribonuclease A (ribonucleate 3'-pyrimidino-oligonucleotidohydrolase; EC 3.1.4.22). A series of overlapping fragments was obtained which allowed the reconstruction of a 361-nucleotide-long 3'-terminal sequence. A unique reading frame could be deduced, which indicated that the replicase gene ends with a U-A-G termination signal and is followed by a 174-nucleotide-long untranslated segment.
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PMID:3'-Terminal nucletide sequence (n equals 361) of bacteriophage MS2 RNA. 80 66

The single-strand specific nuclease S1 from Aspergillus oryzae (EC 3.1.4.21) was purified 600-fold in 16% yield from dried mycelia. Determination of the isoelectric point of S1 nuclease as 4.3-4.4 allowed adjustment of chromatographic conditions such that the enzyme was isolated free of contaminating ribonucleases T1 and T2. S1 nuclease so purified was used for removal of single-stranded portions from the RNA of the Escherichia coli phage MS2, which has a helical content of about 65% in vitro. At 23 degrees, increasing amounts of enzyme converted the RNA to mononucleotides in about equimolar base ratios. No small intermediates of chain length 2-8 were found. At 0 degrees, MS2 RNA hydrolysis was slower and reached, in exhaustive digests, a plateau where 70% of the substrate RNA remained insoluble in 66% EtOH. With [32P]MS2 RNA, strip chart counting of 6% acrylamide-6 M urea electrophoresis patterns of such digests gave recoveries of 80-91% in the form of defined oligomer bands. On 2.5% acrylamide-0.5% agarose gels, the molecular weights of the major oligomers were found to range from 25,000 to 41,000. Similar to purified tRNAArg used as a control, these oligomers were not resistant to pancreatic RNase-RNase T1 hydrolysis at 37 degrees, and were not bound on hydroxylapatite at 50 degrees in 0.14 M sodium phosphate (pH 6.8). Melting of the oligomers gave complex profiles without a clear Tm and showed an increase in A260 of 35% at 93 degrees over that at 28 degrees. Upon formaldehyde denaturation of MS2 RNA prior to S1 nuclease hydrolysis, no resistant oligomers were found.
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PMID:S1 nuclease hydrolysis of single-stranded nucleic acids with partial double-stranded configuration. 118 98

Various agents were tested for their effects on microbial proteases, which activity was monitored by the analysis of cleaved peptide bands in SDS-polyacrylamide gel electrophoresis. Using casein as a substrate, fungal protease (type XIX) was inhibited by the phenyl methyl sulphonyl fluoride, chymostatin, antipain and leupeptin, while bacterial protease (type XXVI) was inhibited by phosphatidyl glycerol, phosphatidyl inositol and sphingosine. MS2 RNA exerted minor inhibition on the bacterial proteolysis of regulatory subunits of cyclic AMP-dependent protein kinase (A-PK). The cleavage of DNA binding protein by both proteases was inhibited, in the presence of MS2 RNA and lambda DNA. In comparison, phosphatidyl serine slightly stimulated the fungal protease on the cleavage of ribonuclease T1. RNA polymerase is a good substrate of the bacterial protease as indicated by the generation of multiple cleaved peptide fragments, whereas alkaline phosphatase is not susceptible to proteolysis.
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PMID:A further study on the regulation of microbial proteases. 222 36

The lysis gene of the RNA bacteriophage MS2 is not expressed unless translation of the overlapping coat gene takes place. To understand the molecular basis for this translational coupling the RNA secondary structure around the lysis gene start was analyzed with structure-specific enzymes and chemicals. The existence of a hairpin between nucleotides 1636 and 1707 is in agreement with the structural mapping data and also with the conservation of base-pairing in the related M12 phage. In this hairpin, the G residues in the Shine and Dalgarno region and start codon are inaccessible to RNase T1, which is consistent with the fact that ribosomal access to the lysis gene is blocked when there is no coat gene translation. Deletions or point mutations that are predicted to destabilize the hairpin give rise to lysis protein synthesis that is independent of coat gene translation. Base substitutions that are not expected to weaken the helix do not lead to independent lysis gene expression. Finally, nucleotide changes that strengthen the hairpin lead neither to uncoupled nor to coupled synthesis of the lysis protein. Structural analysis of mutant MS2 RNA shows that small changes in the stability of the secondary structure lead to substantial differences in translation initiation. The function of the hairpin structure in coupling lysis gene to coat gene translation requires that its stability is kept within narrow limits.
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PMID:Determination of the RNA secondary structure that regulates lysis gene expression in bacteriophage MS2. 365 23

Large fragments of R17, MS2, and Qbeta RNAs were obtained reproducibly by limited digestion by ribonuclease T1. After digestion of R17 and MS2 RNAs, two pairs of large fragments were obtained that probably resulted from specific cleavages of the whole molecules. The cleavages of MS2 RNA were produced at points 36 and 47% from the 5' end.
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PMID:Introduction of specific cleavages into RNAs of RNA bacteriophages for determination of base sequences. 436 31