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 finding was made that a species of ribonuclease is released into mycelial culture media when a wild-type strain of Neurospora crassa was grown on limiting amounts of phosphate. The ribonuclease activity in the fully derepressed state extends to about 60 to 100 fold of that in the repressed state. The synthesis of the ribonuclease was inhibited by the addition of rifampicin, cycloheximide or orthophosphate. Three molecular species of the ribonuclease were found. Two enzyme fractions showing larger molecular weights were suspected to be aggregates containing the enzyme showing the smallest molecular weight (molecular weight of 10 300). All three fractions showed pH optima of around 7, preferential hydrolysis of polyguanylic acid and poor hydrolysis of guanosine 2',3',-cyclic monophosphate. These characteristics were the same as those of ribonuclease N1, and it was suggested that ribonuclease N1 is a repressible extracellular enzyme. Mutations in the genes nuc-1 and nuc-2 caused loss of ability to derepress this enzyme, but heterokaryon between them partially restored the ability. The nuc-1 mutation was epistatic to the nuc-2 alleles which are partly constitutive in the ribonuclease production.
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PMID:Control of the formation of extracellular ribonuclease in Neurospora crassa. 0 54

1. Ribonuclease T1 [EC 3.1.4.8] was inactivated by reaction with tosylglycolate (carboxymethyl rho-toluenesulfonate). At pH 5.5 and 8.0, alkylation of the gamma-carboxyl group of glutamic acid-58 appeared to be the predominant reaction and the major cause of inactivation by tosylglycolate, as in the case of the iodoacetate reaction, although the rate of inactivation was slower than that by iodoacetate. At pH 8.0, histidine residues were also alkylated to some extent. 2. The maximal rate of inactivation was observed at around pH 5.5 and the pH dependence of the rate of inactivation suggested the implication of two groups in the reaction, with apparent pKa values of about 3-4 (possibly histidine residue(s)). 3. In the presence of substrate analogs, ribonuclease T1 was markedly protected from inactivation by tosylglycolate at pH 5.5. The extent of protection corresponded to the binding strength of the substrate analog, except for guanosine. Ribonuclease T1 was much less protected from inactivation by guanosine than by 3'-AMP or 3'-CMP, which has a lower binding strength toward ribonuclease T1. This may indicate that glutamic acid-58 is situated in the catalytic site, at which the phosphate moiety of these nucleotides directly interacts. 4. Enzyme which had been extensively inactivated with tosylglycolate at pH 5.5 scarcely reacted with iodoacetate at pH 5.5, suggesting that these reagents react at the same site, i.e. glutamic acid-58. On the other hand, enzyme which had been inactivated almost completely with tosylglycolate at pH 8.0 still reacted with iodoacetate to some extent at pH 8.0, and the modes of reaction of tosylglycolate and iodoacetate toward ribonuclease T1 appeared to be somewhat different.
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PMID:The structure and function of ribonuclease T1. XX. Specific inactivation of ribonuclease T1 by reaction with tosylglycolate. 1 19

Rainbow trout cell cultures have been exposed to 32P-labelled inorganic phosphate and the labelled RNA has been isolated. The 5S ribosomal ribonucleic acid (5S rRNA) was purified by polyacrylamide gel electrophoresis, then digested with RNase T1 or pancreatic RNase. The products of complete digestion were separated and their sequences determined. These analyses have allowed a sequence to be proposed which differs in eight positions from that of mammalian 5S rRNAs.
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PMID:A proposed nucleotide sequence for the 5S ribosomal ribonucleic acid of rainbow trout (Salmo gairdneri). 11 Apr 24

1. 3'-Guanylyl-ethanol, 3'-guanylyl-propanol, and 3'-guanylyl-alpha-glycerol were synthesized by ribonuclease N1 [EC 3.1.4.8] using guanosine 2',3'-cyclic phosphate as a phosphate donor and various alcohols as phosphate acceptors. The yields of these phosphodiesters were 15%, 13.5%, 38.2%, respectively, with respect to phosphate donor under the optimum conditions. No phosphodiester was synthesized when 2-propanol was used as a phosphate acceptor. Thus, primary alcoholic hydroxyl groups may be regarded as the preferred phosphate acceptor. 2. 3'-Guanylyl-glucose and 3'-guanylyl-ribose were synthesized using glucose and ribose as phosphate acceptors. Under the optimum conditions, the yields of guanylyl-glucose amounted to 52.0%, while that of guanylyl-ribose was much lower. The guanylyl-glucose can be regarded as 3'-guanylyl-6-glucopyranose, based on the results of periodate oxidation. 3. Neither hydroxyamino acids (serine and threonine) nor N-acetylserinamide could be phosphorylated under the conditions used for the above phosphorylations. 4. 3'-Guanylyl-glycerol obtained as above was hydrolyzed by snake venon phosphodiesterase to produce glycerol 3-phosphate. The latter consisted of L-glycerol 3-phosphate (ca 17%) and the D-isomer (ca. 83%). Ribonuclease N1 thus catalyzes an asymmetric synthesis.
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PMID:Synthesis of various phosphodiesters and phosphomonoesters with ribonuclease N. 18 80

The abilities of purine- and pyrimidine-requiring mutants to produce six orthophosphate repressible extracellular enzymes, alkaline phosphatase, 5'-nucleotidase, acid phosphatase, two nucleases and ribonuclease N1 were examined by culturing these mutants in low and high phosphate media containing nucleotide or nucleoside. All the purine requiring mutants produced significantly reduced amounts of alkaline phosphatase, 5'-nucleotidase, acid phosphatase, alkaline nuclease and acid nuclease ranging 0.5-4.2, 5.0-17.4, 25.0-100, 20.3-67.5 and 6.2-48.5%, respectively. Production of ribonuclease N1 was found to be rather stimulated (150-564%) in these mutants. Essentially the same results were obtained for pyrimidine requiring mutants. Among those mutants ad-2 and ad-9 showed relatively high enzyme producing activity. Especially the production of ribonuclease N1 in ad-2 and ad-9 ranged to 4.9- and 5.6-fold that in the wild type. Though nuc-1 mutant (A1) has no ability to produce all these six repressible enzymes, double mutants A1ad-2 and A1ad-9 produced a significant amount of ribonuclease N1 in low and high phosphate media and acid phosphatase in low phosphate media.
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PMID:Control of the Production of orthophosphate repressible extracellular enzymes in Neurospora crassa. 19 39

Vesicular stomatitis virus (VSV) and defective interfering (DI) particle RNAs were labeled at their 3' ends by using RNA ligase and cytidine 3',5'-bis[32P]phosphate. The RNAs were subjected to partial digestion with alkali and analyzed by oligonucleotide fingerprinting in two dimensions. VSV and DI particle RNAs have complete sequence homology for the first eight bases from the 3' end. The following four positions contain three mismatched nucleotides in which guanosine residues in one strand are replaced by uridine residues in the other. There is again complete homology for the next five bases (positions 13-17). The locations of purine residues within the sequence were confirmed by partial digestion with RNase T1 and RNase U2 and separation by size on 20% acrylamide gels. The latter method also indicated that sequences of VSV and DI particle RNAs diverge beyond the 18th nucleotide from the 3' termini.
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PMID:Nucleotide sequence homology at the 3' termini of RNA from vesicular stomatitis virus and its defective interfering particles. 21 Apr 54

Avian sarcoma virus (ASV)-specific RNA was purified from ASV-infected cells by using hybridization techniques which employ polydeoxycytidylic acid-elongated DNA complementary to ASV RNA as well as chromatography on polyinosinic acid-Sephadex columns. The purity and nucleotide sequence composition of purified, virus-specific RNA were established by rehybridization experiments and analysis of labeled RNase T1-resistant oligonucleotides by two-dimensional polyacrylamide gel electrophoresis. Polyadenylic acid-containing RNA purified from ASV-infected cells contained approximately 1 to 4% virus-specific RNA, compared with 0.06 to 0.15% observed in uninfected cells. Sucrose gradient analysis of virus-specific RNA isolated from ASV-infected cells revealed two major classes of polyadenylated viral RNA with sedimentation values of 36S and 26-28S. Cells infected with transformation-defective ASV (virus containing a deletion of the sarcoma gene) contained 34S and 20-22S viral RNA species. Double-label experiments employing infected cells labeled initially for 48 h with [3H]uridine and then for either 30, 60, or 240 min with [32P]phosphate showed that the intracellular accumulation of genome-length RNA (36S) was significantly faster than that of the 26-28S viral RNA species.
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PMID:Purification of virus-specific RNA from chicken cells infected with avian sarcoma virus: identification of genome-length and subgenome-leghth viral RNAs. 21 Dec 52

5 S RNA was isolated from Saccharomyces cerevisiae grown in the presence of 32P-phosphate and digested with nuclease S1, a single-strand specific nuclease. Two different procedures were employed to determine the sites of attack on the RNA. First, 5 S RNA was isolated from nuclease S1 digests, digested to completion with ribonuclease T1, and then 'fingerprinted' by two-dimensional electrophoresis. Quantitation of each of the characteristic RNAase T1-derived oligonucleotides was employed to determine the relative susceptibility of various regions of the molecule to nuclease S1. A second procedure to define nuclease S1-susceptible sites in the molecule employed polyacrylamide gel electrophoretic fractionation of nuclease S1 digests followed by identification of the nucleotide sequences of the released RNA fragments. Both procedures showed that the region of the molecule between residues 9 and 60 was most susceptible to nuclease S1, with preferential cleavage occurring between residues 12-25 and 50-60. These results are discussed in relation to a proposed model for the secondary structure of yeast 5 S RNA.
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PMID:S1 nuclease as a probe of yeast ribosomal 5 S RNA conformation. 37 85

Ultraviolet difference spectral binding studies of ribonuclease T1 with pGp, ApG, CpG, UpG, DGpdA, dGpdC, dGpdG, dGpdT, dTpdG, pdApdG, pdTpdG, pdGpdA, pdGpdG, pdGpdT, c(pdGpdA), and c(pdGpdG) were conducted at pH 5.0, 0.2 M ionic strength and 25 degrees C. Under these conditions, the characteristic difference spectrum and association constant for (1:1) ribonuclease T1 binding were determined for each ligand. The binding of guanosine and deoxyguanosine containing ligands could be distinguished by the shapes of their difference spectra. The results indicated that the guanine moiety of each ligand was bound at the enzyme's primary recognition site. Evidence of a specific enzyme subsite for binding the adenine moiety of ApG and pdApdG is presented. The proposal of a specific enzyme subsite for binding the 5'-phosphate group of a complexed guanosine moiety (Sawada, F., Samejima, T., and Saneyoshi, M. (1973), Biochim. Biophys. Acta 299, 596) is not supported in the present work. Preliminary evidence for the existence of two additional enzyme subsites and the effect of oligomer conformation on enzyme binding are also discussed.
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PMID:Subsite interactions of ribonuclease T1: binding studies of dimeric substrate analogues. 82 Mar 74

The methionine acceptor activity of a crude tRNA from bakers' yeast was resolved into two peaks (I and II) by column chromatography on DEAE-Sephadex A-25 with a 1 M phosphate system. Methionine tRNA from peak II was not formylated by E. coli methionyl-tRNA transformylase [EC 2.1.2.9.] after being charged with methionine, whereas that from peak I was formylatable under the same conditions. A substantial amount of unlabelled methionine tRNA, tRNAMetm, was highly purified from the peak II fraction by successive chromatographic procedures. The purified tRNAMetm was digested with pancreatic ribonuclease A [EC 3.1.4.22] and ribonuclease T1 [EC 3.1.4.8]. The digestion products were isolated into individual components and completely sequenced. The results of sequence analysis of the two RNase digests were in good agreement and indicated that the chain length of this tRNA is 76, including 13 modified nucleotides. These oligonucleotide fragments can be constructed into a unique total sequence, assuming a few conventional features of clover leaf structure for the tRNA was established by analyses of partial digestion products with RNase T1, as reported in the accompanying paper.
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PMID:The primary structure of non-initiator methionine transfer ribonucleic acid from Bakers' yeast. I. Purification and complete digestion with ribonuclease T1 and pancreatic ribonuclease A. 82 24


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