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)

The influence of tRNA on the kinetics of PP-ATP exchange and aminoacyl-tRNA formation catalysed by leucyl-, phenylalanyl-, and tryptophanyl-tRNA synthetases has been investigated. These enzymes were chosen because they belong to three main classes of quaternary structure alpha1, alpha2beta2 and alpha2, respectively. The present paper shows that the investigated synthetases manifest kinetic cooperativity of the active centres which is negative in the case of AAA formation and positive in the case of leucyl- and tryptophanyl-tRNA synthesis. The obtained data were interpreted with the aid of the trigger model of the enzyme.
Mol Biol Rep 1976 Jul
PMID:Interaction of aminoacyl-tRNA synthetases and tRNA: positive and negative cooperativity of their active centres. 18 1

The cytochrome c oxidase subunit I (COI) gene sequences from planarian (Dugesia japonica) DNA, most probably of mitochondrial origin, are heterogeneous. Taking advantage of the heterogeneity that occurs primarily in silent sites of the COI DNA sequences, amino acid assignments of several codons have been deduced as nonuniversal: UGA = Trp, AAA = Asp, and AGR (R: A or G) = Ser. In addition, UAA, a stop codon in the universal genetic code, is tentatively assumed to be a tyrosine codon, because three of the sequences examined have UAA at the well-conserved tyrosine site of UAY (Y: U or C) in other planarian sequences as well as in the mitochondria of human, Xenopus, sea urchin, Drosophila, Trypanosoma, and Saccharomyces cerevisiae. AUA would most probably be an isoleucine codon in these mitochondria, whereas it is a methionine codon in the majority of nonplant mitochondria.
J Mol Evol 1992 Apr
PMID:Planarian mitochondria. II. The unique genetic code as deduced from cytochrome c oxidase subunit I gene sequences. 131 9

Previous genetic analyses indicated that translational frameshifting in the--1 direction occurs within the run of six adenines in the sequence 5'-TTAAAAAACTC-3' at nucleotide positions 305-315 in IS 1, where the two out-of-phase reading frames insA and B'-insB overlap, to produce transposase with a polypeptide segment Leu-Lys-Lys-Leu at residues 84-87. IS 1 mutants with a 1 bp insertion, which encode mutant transposases with an amino acid substitution within the polypeptide segment at residues 84-87, did not efficiently mediate cointegration, except for an IS 1 mutant which encodes a mutant transposase with a Leu-Arg-Lys-Leu segment instead of Leu-Lys-Lys-Leu. An IS 1 mutant with the DNA segment 5'-CTTAAAAACTC-3' at positions 305-315 carrying the termination codon TAA in the B'-insB reading frame could still mediate cointegration, indicating that codon AAA for Lys corresponding to second, third and fourth positions in the run of adenines is the site of frameshifting. The beta-galactosidase activity specified by several IS 1-lacZ fusion plasmids, in which B'-insB is in-frame with lacZ, showed that the region 292-377 is sufficient for frameshifting. The protein produced by frameshifting from the IS 1-lacZ plasmid in fact contained the polypeptide segment Leu-Lys-Lys-Leu encoded by the DNA segment 5'-TTAAAAAACTC-3', indicating that--1 frameshifting does occur within the run of adenines.
Mol Gen Genet 1992 Nov
PMID:Identification of the site of translational frameshifting required for production of the transposase encoded by insertion sequence IS 1. 133 29

Low-frequency restriction fragment analysis of more than 100 strains of the genus Frankia showed that restriction enzyme DraI (recognition site, TTT'AAA) gave rise to large DNA fragments (200 to 1,500 kb), which, when they were subjected to cluster analysis, reflected the host plants from which the strains were isolated. Our results support the conclusions of Lalonde and his colleagues (M. Lalonde, L. Simon, J. Bousquet, and A. Seguin, p. 671-680, in H. Bothe, F. J. de Bruijn, and W. E. Newton, ed., Nitrogen Fixation: Hundred Years After, 1988; P. Normand, P. Simonet, and R. Bardin, Mol. Gen. Genet. 213:238-246, 1988) and Fernandez et al. (M. P. Fernandez, H. Meugnier, P. A. D. Grimont, and R. Bardin, Int. J. Syst. Bacteriol. 39:424-429, 1989) that various biochemical and genomic analyses can give rise to groupings of Frankia strains that are consistent with the host plants from which the strains are isolated and that the resulting groups may form a basis for defining Frankia species.
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PMID:Low-frequency restriction fragment analysis of Frankia strains (Actinomycetales). 135 77

About 50% of Japanese have been estimated to possess at least one ALDH2*2 allele with a substitution of AAA for GAA at codon 487 of the aldehyde dehydrogenase gene. This mutation is tightly associated with the sensitivity of an individual to alcohol. We developed a method of identifying the ALDH2*2 allele by a non-radioactive technique. DNA from individuals was subjected to polymerase chain reaction in which part of the aldehyde dehydrogenase 2 gene was amplified. After dot-blotting onto nylon membranes, the DNA was hybridized with biotin-labelled allele-specific oligonucleotides. Determination of genotypes on 77 unrelated healthy Japanese individuals, using the conventional method and our new method with gradient hybridization temperature and competitive oligonucleotides, indicated that the latter was superior to the former.
Mol Cell Probes 1992 Aug
PMID:A non-radioactive method for the detection of a common mutant allele of aldehyde dehydrogenase 2. 152 4

The inherent infidelity of Taq DNA polymerase in the polymerase chain reaction was exploited to produce random mutations in the trp A gene. Screening of the resulting clones allowed selection of non-interactive mutant alpha subunits retaining their intrinsic catalytic activity. Two single changes responsible for this phenotype were identified by DNA sequencing as: alpha 126 valine (GTG)----glutamic acid (GAG) and alpha 128 valine (GTT)----aspartic acid (GAT). Three single changes giving a non-interactive phenotype with an impaired intrinsic catalytic activity were identified by DNA sequencing as alpha 66 asparagine (AAC)----aspartic acid (GAC); alpha 109 lysine (AAA)----arginine (AGA); alpha 118 cysteine (TGC)----arginine (CGC). Where possible, we individually assessed the importance of these residues in alpha beta interaction in light of structural information from X-ray crystallography and by intergeneric protein sequence comparison.
Mol Gen Genet 1992 May
PMID:Selection and analysis of non-interactive mutants in the Escherichia coli tryptophan synthase alpha subunit. 160 55

A polymerase chain reaction method was carried out to address the possible presence of estrogen receptor (ER) mutations in murine transformed cell lines. The segment of ER cDNA coding the C and D domains was amplified and cloned into pUC 19. Mammary carcinoma cell line (SC-3) did not show any mutation in this segment. However, the sequence analysis of ER in the Leydig cell line (B-1 F) revealed a single base change at acidic Glu-279 (GAA) to basic Lys-279 (AAA) compared with murine uterus ER cDNA. The biological significance of this mutation is discussed.
J Steroid Biochem Mol Biol 1991 Jul
PMID:A single nucleotide substitution in the D domain of estrogen receptor cDNA causes amino acid alteration from Glu-279 to Lys-279 in a murine transformed Leydig cell line (B-1 F). 167 3

Hepatitis B surface antigen (HBsAg) particles carry the common determinant, a, as well as d or y and w or r subtype determinants, and are classified into the four major subtypes, i.e., adw, adr, ayw and ayr. Rare sera contain HBsAg particles with all four subtype determinants (adywr). Target sequences (nucleotides 38-550) in the S gene of hepatitis B virus (HBV) DNA in two such sera were amplified by the polymerase chain reaction. Individual amplification products were cloned in an M13 phage vector. The HBV DNA clones obtained were subtyped by determining the second letters of codon 122 and 160 for lysine (AAA/AAG) or arginine (AGA/AGG), which specify the d or y and w or r determinants, respectively. From one serum (S-63), two adw, 10 adr and 58 ayr clones were obtained. When the two adw clones and two representatives each of the adr and ayr clones were compared against each other, for the sequence of 235 base pairs representing nucleotides 295-529 in the S gene, they differed only by 0.4-2.1% (average 1.2%). These results indicated multiple point mutations of a single HBV strain of subtype ayr and co-infection of hepatocytes with the original HBV strain and its mutant of subtype adw as the mechanism for the production of HBsAg/adywr particles. From the other serum (K-45), 1 adw, 73 adr and 4 ayw clones were obtained. The adw clone and two representative adr clones differed only by 0-1.7% in the S gene sequences, but they differed by 8.5% or greater from two representative ayw clones. HBsAg/adywr particles in this serum, therefore, could be explained by double infection of hepatocytes with two HBV strains of different subtypes (adr and ayw).
Mol Immunol 1990 May
PMID:Hepatitis B surface antigen particles with all four subtypic determinants: point mutations of hepatitis B virus DNA inducing phenotypic changes or double infection with viruses of different subtypes. 169 59

In our previous study, a drastic change in terminal saccharides of glycoconjugates of the hamster zona pellucida associated with oocyte maturation was observed using light microscopic methods of lectin cytochemistry. To understand the mechanism of this change, in the present study, the correlation between the cytochemical appearance of saccharide residues in the zona pellucida and nuclear maturation was examined. Immature hamsters were treated with PMSG and hCG to induce follicular development and ovulation. The animals were euthanized 0 to 26 hrs. after the injection of PMSG or 0,1,2,3,4,5,7,9 or 11 hrs. after the injection of hCG, and ovaries were dissected out, fixed, paraffin embedded and sectioned serially. Every other paraffin section was stained with hematoxylin to observe the status of nuclei and to classify follicular growth and only the fully developed preovulatory follicles were examined in experiments. The peroxidase-labelled lectin-diaminobenzidine procedure was applied to sections. The lectins employed were WGA, SBA, MPA, UEA-I, LotusA and AAA. Germinal vesicle breakdown was observed within 3 hrs. after the administration of hCG. A positive reaction of WGA, SBA or MPA for zonae pellucidae in the fully developed preovulatory follicles appeared 1 hr. after hCG injection, and remained so for the next 10 hrs. UEA-I, Lotus A and AAA reactions were negative for all of the zonae pellucidae observed. The data indicate that the synthesis of saccharide residues such as GlcNAc and GalNAc forming zona components in the follicles is not triggered by germinal vesicle breakdown.
Cell Mol Biol 1991
PMID:Appearance of lectin binding affinity to the zona pellucida during hamster oocyte maturation. 174 97

Differences in assignments from those in the universal genetic code occur in codes of mitochondria. In this report, the published sequences of the mitochondrial genes for COI and ND1 in a platyhelminth (Fasciola hepatica) are examined and it is concluded that AAA may be a codon for asparagine instead of lysine, whereas AAG is the sole codon for lysine in this species.
J Mol Evol 1990 Apr
PMID:Evolution of the mitochondrial genetic code. IV. AAA as an asparagine codon in some animal mitochondria. 211 47


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