Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Yeast tRNAlVal alkylation with 2',3'-0-[4-(N-2-chloroethyl-N-methylaminobenzylidene]dpCdpGrpA proceeds within complementary complexes that are formed due to attachment of the reagent to three sequences of tRNAlVal. The acetal bond of the initial product of alkylation has been hydrolyzed to yield beta-[N=methyl-N-(4-formylphenyl) amino]ethyl-tRNAlVal (R-tRNA) that contains from 1 to 3 residues of the specifically modified nucleosides: alkyl adenosine (R-A), R-I and probably R-psi. Individual alkylated oligonucleotides were isolated from R-tRNAlVal pyrimidyl-RNAse digest. The alkylated oligonucleotides correspond to 93% of all modified products. The major component is beta-[N-methyl-N(4-formylphenyl)aminoA1ethyl-A53-G-Tp. This indicates that the reagent is attached to complementary psi-C-G-sequence in the T-loop of tRNAlVal and that alkylation of the third nucleotide counting from the 5'-terminus of the sequence which binds the reagent completely takes place within the complementary complexes. This site of the tRNAlVal is modified quantitatively at 20 degrees and 19-fold excess of the reagent. The alkylation of two other sites of tRNA reaches 50% under these conditions.
Mol Biol (Mosk)
PMID:[Complementarily addressed alkylation of yeast tRNA 1 Val with chloroethylmethylaminobenzylidene d(pC-G)-A. Proof of the modification of the third nucleotide located at the 5'-terminus of the complete binding site of the reagent]. 80 83

Conformational transitions in tRNAfMet E. coli the initiator tRNA in bacterial systems and in some other individual tRNAs have been studied as a function of monovalent and divalent ion concentrations. By measuring the extent of energy transfer between dye molecules adsorbed on tRNAs and by study of adsorption isotherms of dyes on tRNAs conclusion has been drawn about the similarity of conformational state of all tRNAs studied at low ionic strength (mu 0.01). A conformational change in tRNA, produced by an addition of Mg2+ and Na+ ions results in more than two fold decrease of the strong binding sites for dyes. A marked difference in the adsorption properties of tRNAfMet in comparison with other investigated tRNAs were found. The tRNAfMet was the only tRNA species that did not form the strong type of complexes with dyes at high ionic strength
Mol Biol (Mosk)
PMID:[Conformational transitions in tRNA fMet from E. coli induced by monovalent and divalent ions]. 80 88

The mechanism of 5'-cytidilic acid stimulation of the reaction between 2'(3')-O-formylmethionine ester of 5'-adenylic acid and phenylalanyl-tRNA catalyzed by E. coli ribosomes has been studied. It has been shown that cytidilic acid binds to the donor site of the peptidyltransferase in the area which is usually occupied by the second nucleotide residue of the peptidyl-tRNA 3'-end. After the binding cytidilic acid stimulates effectively the donor activity of formylmethionine ester of adenylic acid. A number of compounds have been tested as possible stimulants. Both the chemical nature of stimulant and its conformation are important for the stimulating action. A hypothetic scheme is suggested explaining possible causative factors of peptidyl-tRNA translocation from the acceptor site to the donor site after peptide bond formation.
Mol Biol (Mosk)
PMID:[Donor site of E. coli ribosomal peptidyltransferase]. 80 87

The in vitro B. subtilis protein synthesizing system is very restricted in its ability to translate E. coli phage messenger RNA's, specifically phage T4 RNA, even though it actively translates its proper mRNA species. In contrast, the E. coli system translates with similar efficiency mRNA from either source. The initiation factors from the two systems are functionally interchangeable. The 30S B. subtilis ribosomal subunit is responsible for the limited template specificity of the B. subtilis ribosomes. Although the efficiency of the T4RNA directed F Met-tRNA binding by B. subtilis ribosomes is less than that of SPOI RNA-directed binding, the most restrictive step in the translation of T4RNA by B. subtilis ribosomes appears to be at the level of the formation of the first peptide bond, as measured by F Metpuromycin formation.
Mol Gen Genet 1976 Dec 31
PMID:Selective messenger translation by Bacillus subtilis ribosomes. 81 1

4-N-2-chloroethyl-N-methylamino-benzaldehyde acetal derivatives (RCL-derivatives) of octauridylic and nanauridylic acids were used to localize the structures organizing mRNA-binding site of ribosomes. These derivatives, like free oligonucleotides, stimulate binding of 14C-phenylalanyl-tRNA to ribosomes. They effectively alkylate ribosomes within the specific complex. The extent of 30S subunit alkylations is much greater than that of 50S subunit, alkylation being completely inhibited by preincubation with polyridylic acid, suggesting that the chemical alteration occurs near mRNA-binding site. Both rRNA and proteins undergo modification in 30S subunit (75% and 25% of the total 30S subunit modification, respectively).
Mol Biol (Mosk)
PMID:[Specific chemical modification of ribosomes in the vicinity of their mRNA-binding center]. 94 May 55

The rates of tryptophanyl-tRNA formation catalyzed by beef pancreas tryptophanyl-tRNA synthetase were measured in a concentration range of each substrate (tryptophan, ATP and yeast tRNATrp) and also in the presence of various concentrations of substrate analogues (tryptamine and alpha,beta-methylene analogue of ATP) concentrations. The data obtained were compared with the kinetic equations which described various possible mechanisms of the reaction. The comparison of the mechanisms was based on the calculation of relative probabilities of each hypothesis the efficiency of which was demonstrated earlier. The calculations have shown that two mechanisms according to which the intermediate enzyme-aminoacyl-adenylate complex formation involves the enzyme-aminoacyl-tRNA complex are the most probable ones.
Mol Biol (Mosk)
PMID:[The mechanism of the reaction forming tryptophanyl-tRNA, catalyzed by tryptophan:tRNA-ligase]. 94 May 60

Rat liver ribosome treatment with ethanol and 1 M NH4Cl releases some 31-33 ribosomal proteins. This split protein fraction binds Phe-tRNA, Ac-Phe-tRNA, Met-tRNAM and f-Met-tRNAF in the absence of K+ and Mg++ ions. When the split protein fraction is passed through Sephadex G-100 only six proteins are retained in the column: S10, S14, S15, S19, L35, and L36. The aminoacyl-tRNA binding activity of this protein fraction retained in the Sephadex G-100 column is similar to that of the total split protein fraction, suggesting that the above six proteins, or only some of them, are involved in the binding reaction.
Mol Biol Rep 1976 Jul
PMID:Binding of aminoacyl-tRNA to rat liver ribosomal proteins. 95 16

Transfer RNA was isolated from calvaria prepared from chick embryos incubated for 15-17 days. The chargeability of the unfractionated tRNA with ten amino acids tested was very similar to that of unfractionated tRNA from adult chicken liver when data were expressed on the basis of pmoles of amino acceptance per A260 unit of tRNA. However, the relative amount of tRNA in calvaria is only about one-fourth the amount in liver. Analysis of individual species of tRNA by two-dimensional electrophoresis on polyacrylamide gels shows that there are fewer isoaccepting species of tRNA in calvaria than in liver.
Mol Biol Rep 1976 Jul
PMID:Transfer RNA of a collagen producing tissue, chick-embryo calvaria. 98 43

Oligomers of chromatin subunits (oligonucleosomes) were prepared by a mild digestion of chromatin with staphylococcal nuclease followed by a purification of a high molecular weight material (hexanucleosomes and larger DNP particles) by gel chromatography. The main finding is that a mild removal of histone H1 from the oligonucleosome preparation by treatment with tRNA in the absence of any significant hydrodynamic shearing leads to the formation of free DNA molecules which constitute 5-6% of the total oligonucleosomal DNA. The size of nucleosome-free DNA stretches in H1-depleted hydrodynamically sheared chromatin is about 6000 base pairs and their content is apparently 10-12% of the total DNA. These and related findings are discussed in terms of the previously proposed "asymmetric hairpin" model of DNA packing in chromatin [1-4]. Different kinds of the asymmetric hairpin are considered and ambiguities in interpretations of experimental data are pointed out.
Mol Biol Rep 1976 Sep
PMID:Free DNA stretches in histone H1-depleted chromatin and their possible relation to chromomere structure. 100 4

Alkylating analogs of peptidyl-tRNA: N-chloroambucilyl-14C-phenylanalyl-tRNA (1), N-iodoacetyl-14C-phenylalanyl-tRNA (2) and N-bromo-acetyl-14C-phenlalanyl-tRNA (3) were applied for the modification of the peptidyl-transferase center of the 80S ribosomes from rat liver. These analogs, being in the teronary complex poly-U: ribosome : tRNA analog, modified ribosomal proteins and ribosomal RNA. The modification is directed to large ribosomal subunit. It is found, that (1) modifies ribosomal proteins L5, L25, L31 and L32 and (2) modifies ribosomal proteins L4, L6, L10+L11, L13 and L30.
Mol Biol (Mosk)
PMID:[Modifications of ribosomes from rat liver with alkylating derivatives of tRNA]. 105 50


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