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)

In S. cerevisiae four isoacceptor mitochondrial tRNAs for serine have been separated by reversed phase chromatography. At least two of these species are products of different genes. In this work the deletion mapping technique has been used to locate two genes for tRNAser. The gene for tRNAser previously localized in the oli I region of the mitochondrial genome has been found to code for tRNAser2, and another gene coding for tRNAser1 has been detected in the region where most of other tRNA genes are found. Results of fine mapping experiments allowed to localize this gene in the proximity of the gene for tRNAarg.
Mol Gen Genet 1979 Aug
PMID:Two isoaccepting seryl tRNAs coded by separate mitochondrial genes in yeast. 39 Mar 1

Peptidyl tRNA hydrolase is an essential enzyme for normal growth inasmuch as a mutant strain of Escherichia coli with a temperature-sensitive hydrolase cannot continue protein synthesis at the non-permissive temperature. In the absence of hydrolase peptidyl tRNA rapidly accumulates. Why peptidyl tRNA should be formed is the subject of this report. The rapid rate of protein synthesis is likely one mechanism of formation of peptidyl tRNA. A strA mutant of the hydrolase (pth-1) mutant strain that has a 40% reduction in amino acid polymerization rate can grow at 42 degrees C. StrA mutants with normal polymerization rates, however, cannot grow at 42 degrees C when pth-1 is present. Furthermore, addition of low levels of chloramphenicol (2--4 micrograms/ml) but not several other tested drugs, phenotypically suppressed pth-1 at 42 degrees C. Chloramphenicol, at these concentrations, was found to reduce the amino acid polymerization rate 30--40%. On the other hand, no evidence could be found that amino acyl tRNA selection errors are incorporated into pseudo revertants of the pth-1 strain.
Mol Gen Genet 1979 Oct 01
PMID:Natural premature protein synthesis termination can be reduced in Escherichia coli by decreased translation rates. 39 30

Cytosine residues in 32P-labeled E. coli tRNA Leu 1 were modified by treatment of the tRNA with the semicarbazide-bisulfite reagents [Hayatsu, H. (1976) Biochemistry 15, 2677-2682]. Analysis of the modification sites showed that only four cytidine residues, i.e. C35, C53, C85 and C86, reacted. They were identical with the cytidines of this tRNA accessible to methoxyamine [Chang, S. E. and Ish-Horowicz, D. (1974) J. Mol. Biol. 84, 375-388] and the accessibility was consistent with the conformational features recognized for tRNA in general. The rapidity and the simple nature of this modification demonstrate that the semicarbazide-bisulfite reaction is a useful tool in studying conformations of polynucleotides.
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PMID:A rapid cytosine-specific modification of E. coli tRNA Leu 1 by semicarbazide-bisulfite, a probe for polynucleotide conformations. 40 97

Cell-free protein synthesizing systems were prepared from the livers of chick embryos at selected ages and the characteristics of individual fractions were compared. While polysomes showed decreasing size with older embryos, isolated polysomes did not differ significantly in amino acid incorporating activity when assayed with standard cell sap. When assayed with standard polysomes, cell sap activity decreased with increasing developmental age whether incorporation was measured using (3H)lysine, (3H)leucine, or [3H]aminoacyl-tRNA. Free amino acid concentrations in the cell sap showed reproducidble independent variation during development which was taken into consideration in calculating net amino acid incorporation. A larger increase in ribonuclease activity was observed during development; however, nuclease inhibitor activity was absent before day 15 but increased thereafter. Aminoacyl-tRNA sythetase activity did not vary significantly. It is proposed that the observed changes in the rate of cell-free protein synthesis result not only from increasing ribonuclease activity with increasing developmental age but also from changes in the activity of other soluble factors.
Mol Cell Biochem 1979 Apr 02
PMID:Polymorphism in fowl serum albumin. VI. Changes in in vitro protein synthesizing activity in developing embryonic fowl liver. 46 Jan 76

The conformation analysis of tRNA acceptor fragment XCCA (X=A) was performed. The ribose conformation was taken rigid C(3')-endo. The optimum conformation was found for the ACCA fragment. It was shown that the omega, omega'-angle of the terminal adenine in any crystal modification of the yeast tRNAFen is not optimal. The conformation mobility of the 3'-end ACCA fragment was calculated in the vicinity of optimum conformation. Redundant energy required for keeping the correct 3'-terminal tRNA orientation about the enzyme catalytic centre during any small orientation distortions of the non-universal X-nucleotide relative to the enzyme was estimated. The distortions may occur when non-gomologous tRNA interact with aminoacyl-tRNA-synthetase. It was found that redundant energy for 3' displacement is very anisotropic and some small X-nucleotide reorientation may decrease the catalitic velocity of aminoacylation u0(4)--10(5) times.
Mol Biol (Mosk)
PMID:[Conformation mobility of the universal acceptor end of tRNA]. 46 Jan 87

The effect of elongation factor (EF) Tu, bound to the ribosome with the help of poly(uridylic) acid, Phe-tRNA and guanyl-5'-yl methylene diphosphonate, on the conformation and/or chemical environment of ribosomal proteins has been examined using, as a probe, protein iodination. Ribosomes complexed only with poly(uridylic acid) and Phe-tRNA have been used as a control. EF-Tu on the ribosome significantly increases the iodination of proteins S7, S10 and L3 and decreases that of S21 and L18.
Mol Biol Rep 1979 Aug 31
PMID:Elongation factor Tu-induced conformational changes of ribosomes detected by iodination. 49 64

Sequence data from methionine initiator and phenylalanine transfer RNAs were used to construct phylogenetic trees by the maximum parsimony method. Although eukaryotes, prokaryotes and chloroplasts appear related to a common ancestor, no firm conclusion can be drawn at this time about mitochondrial-coded transfer RNAs. tRNA evolution is not appropriately described by random hit models, since the various regions of the molecule differ sharply in their mutational fixation rates. "Hot" mutational spots are identified in the Tpsic, the amino acceptor and the upper anticodon stems; the D arm and the loop areas on the other hand are highly conserved. Crucial tertiary interactions are thus essentially preserved while most of the double helical domain undergoes base pair interchange. Transitions are about half as costly as transversions, suggesting that base pair interchanges proceed mostly through G-U and A-C intermediates. There is a preponderance of replacements starting from G and C but this bias appears to follow the high G + C content of the easily mutated base paired regions.
J Mol Evol 1979 Dec
PMID:Evolution of methionine initiator and phenylalanine transfer RNAs. 53 8

3-Amino-1-chloro-indolwbutan-2-one (Trp-CH2Cl) was synthesized to be used for labeling the active site of tryptophanyl-tRNA-synthetase. Trp-CH2Cl irreversibly inhibits the beef pancreas tryptophanyl-tRNA synthetase activity. The inhibition rate was found to exhibit saturation concentration dependence typical for an affinity reagent. L-tryptophan and L-tryptophanyl adenylate protect the enzyme from inhibition. To determine the stoichiometry of inhibitor--protein binding 3H-label from NaB3H4 was incorporated into the modified enzyme. The molar ratio of inhibitor residues incorporated into the modified enzyme (dimeric molecule) is approximately 2. When one of the subunits of the enzyme was reversibly protected with relatively stable tryptophanyl adenylate, the modification of this enzyme led to the blocking of the other subunit (so called "one-site" enzyme). Some properties of the "one-site" enzyme obtained were studied.
Mol Biol (Mosk)
PMID:[Affinity modification of tryptophanyl-tRNA synthetase by an alkylating L-tryptophan analog]. 54 76

Three forms (E1, E2 and E3) of leucyl-tRNA synthetase (LeuRS) were separated by DEAE-cellulose chromatography of total aminoacyl-tRNA synthetases from cow lactating mammary gland. The method of purification of all three components is described. E1 is a dimeric molecule (alpha 2) of molecular weight 182 000. Two other forms of molecular weight 67 000 and 64,000 consist of a single polypeptide chain as determined by polyacrylamide gel electrophoresis. Optimum conditions and kinetic parameters of leucyl-tRNA formation were studied for every enzyme form. The low values of Vmax and thermostability are characteristic of E3. All forms of LeuRS interact with 6 isoaccepting tRNA(Leu) from lactating mammary gland and can activate leucine in the absence of tRNA. E2 and E3 are supposed to derive from the native enzyme by endogenous proteolysis. The physico-chemical properties of native LeuRS from lactating mammary gland are compared with those of LeuRS's from other sources.
Mol Biol (Mosk)
PMID:[Purification and properties of leucyl-tRNA synthetase from the cow mammary gland]. 57 75

A comparative study of rat kidney and carcinoma RA tRNA-methylase activity has been carried out using partially purified enzyme preparations and total E. coli tRNA. Also the nuclease activity of the methylase preparations from kidney and carcinoma was compared. It was established that the methylase activity in carcinoma preparations is higher, whereas the nuclease activity is lower in comparison to the enzyme preparations from liver. No formation of some specific methylated compounds could be established in the case of carcinoma. It was established that the relative contribution of individual methylases to the elevated level of total tRNA-methylase activity in carcinoma is different. Maximal enhancement of activity was established for the methylase forming m5U, whereas the activity of the enzymes, transfering the methyl group to the fifth position of C is practically equal in kidney and carcinoma tissues. Experimental results and theoretical evaluation of the hypotheses suggested to explain the higher methylase activity in tumor tissues allowed to reject some of them.
Mol Biol (Mosk)
PMID:[Comparative study of the tRNA-methylases of normal and tumor tissues. I. Spectrum of renal and carcinoma RA methylases]. 61 45


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