Tryptophanyl-tRNA synthetase is found closely associated with and stimulates DNA polymerase α-like activity from wheat embryos

Castroviejo, Michel; Fournier, Michel; Gatius, M.; Gandar, J.; Labouesse, Bernard; Litvak, Simón

doi:10.1016/0006-291x(82)91703-x

Cited by 18 publications

(3 citation statements)

References 18 publications

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“…Most of these enzymes share with the animal polymerase the inability to use a poly rA-oligo dT template, as well as the strong inhibition at high ionic strength. In the case of the wheat enzyme, we have also observed that both polymerases of the a type are highly resistant to dideoxyTTP (17).…”

Section: Dna Polymerases Found In Plant Cellsmentioning

confidence: 69%

Plant DNA polymerases

Litvak

Castroviejo

1985

Plant Mol Biol

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Section: Dna Polymerases Found In Plant Cellsmentioning

confidence: 69%

Plant DNA polymerases

Litvak

Castroviejo

1985

Plant Mol Biol

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“…Another possibility is that Ap4A might serve a substrate function rather thati that of an allosteric effector, in which case the flux could change with no observed change in concentration. These possibilities are of interest in view of the postulation that Ap4A could serve as a primer for DNA replication (53) and the observed association of certain tRNA synthetases (9,44) Ap4A levels in simian virus 40-transformed 3T3 cells were the same as those in normal 3T3 cells (2). Ap4A did not stimulate DNA synthesis in permeabilized, normal human fibroblasts (14) under conditions used to demonstrate Ap4A stimulation of DNA synthesis in baby hamster kidney cells (21).…”

Section: Resultsmentioning

confidence: 99%

In vivo levels of diadenosine tetraphosphate and adenosine tetraphospho-guanosine in Physarum polycephalum during the cell cycle and oxidative stress.

Garrison¹,

Mathis²,

Barnes³

1986

Mol. Cell. Biol.

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Cellular levels of diadenosine tetraphosphate (Ap4A) and adenosine tetraphospho-guanosine (Ap4G) were specifically measured during the cell cycle of Physarum polycephalum by a high-pressure liquid chromatographic method. Ap4A was also measured indirectly by a coupled phosphodiesterase-luciferase assay. No cell cycle-specific changes in either Ap4A or Ap4G were detected in experiments involving different methods of assay, different strains of P. polycephalum, or different methods of fixation of macroplasmodia. Our results on Ap4A are in contrast with those reported previously (C. Weinmann-Dorsch, G. Pierron, R. Wick, H. Sauer, and F. Grummt, Exp. Cell Res. 155:171-177, 1984). Weinmann-Dorsch et al. reported an 8-to 30-fold increase in Ap4A in early S phase in P. polycephalum, as measured by the phosphodiesterase-luciferase assay. We also measured levels of Ap4A, Ap4G, and ATP in macroplasmodia treated with 0.1 mM dinitrophenol. Ap4A and Ap4G transiently increased three-to sevenfold after 1 h and then decreased concomitantly with an 80% decrease in the level of ATP after 2 h in the presence of dinitrophenol. These results do not support the hypothesis that Ap4A is a positive pleiotypic activator that modulates DNA replication, but they are consistent with the hypothesis proposed for procaryotes that ApA and Ap4G are signal nucleotides or alarmones of oxidative stress (B.

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“…The presence of D-aminoacyl-tRNA deacylase activity in a protein involved in DNA replication is intriguing in view of the tight binding and stimulation of DNA polymerase ␣ enzymes from wheat embryos and HeLa cells by threonyl-tRNA synthetases (54,55) and the strong structural resemblance of accessory ␤ subunits of animal mitochondrial DNA polymerases to tRNA synthetase enzymes (56,57). Indeed, constituents of the aminoacyl-tRNA synthetase complex containing nine synthetases and three interacting multifunctional proteins (AIMPs) carry out diverse functions as cell cycle-related signal- ing molecules.…”

Section: Resultsmentioning

confidence: 99%

Structure and Function of the c-myc DNA-unwinding Element-binding Protein DUE-B

Kemp

Bae

et al. 2007

Journal of Biological Chemistry

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Local zones of easily unwound DNA are characteristic of prokaryotic and eukaryotic replication origins. The DNA-unwinding element of the human c-myc replication origin is essential for replicator activity and is a target of the DNAunwinding element-binding protein DUE-B in vivo. We present here the 2.0 Å crystal structure of DUE-B and complementary biochemical characterization of its biological activity. The structure corresponds to a dimer of the N-terminal domain of the full-length protein and contains many of the structural elements of the nucleotide binding fold. A single magnesium ion resides in the putative active site cavity, which could serve to facilitate ATP hydrolytic activity of this protein. The structure also demonstrates a notable similarity to those of tRNA-editing enzymes. Consistent with this structural homology, the N-terminal core of DUE-B is shown to display both D-aminoacyl-tRNA deacylase activity and ATPase activity. We further demonstrate that the C-terminal portion of the enzyme is disordered and not essential for dimerization. However, this region is essential for DNA binding in vitro and becomes ordered in the presence of DNA.During each division of somatic cells DNA replication is regulated so that the genome is copied in its entirety only once (1, 2). The classical replicon hypothesis states that the initiation of DNA replication at replication origins is controlled by initiator protein binding at regulatory sites called replicators and has served as a useful description for prokaryotic replication (3). In contrast, a concise description of eukaryotic replication is complicated by the fact that eukaryotic chromosomes contain multiple origins of replication and the replicator sequences controlling them do not share easily recognizable conserved sequences (4, 5). However, a structure common to yeast and mammalian origins of replication is a region of easily unwound DNA termed a DNAunwinding element (DUE) 3 (6 -13). Replication initiates within a 3.5-kb region upstream of the human c-myc gene (14 -16). Semi-conservative DNA synthesis was shown to originate in this region using nascent DNA abundance assays in chromosomal and plasmid-based systems in vitro and in vivo (13, 16 -26). Transposition of a 2.4-kb c-myc origin fragment to an ectopic site in the HeLa genome promotes bidirectional DNA replication initiation at the site of insertion, confirming its function as a chromosomal replicator (13,22). This 2.4-kb region contains an AT-rich region comprising three matches to the Saccharomyces cerevisiae ARS consensus sequence and a ϳ40-bp DUE zone of predicted helical instability, also termed the far upstream element or FUSE (27), which has been shown to be sensitive to single stranddirected reagents in vitro and in vivo (19,27). Deletion of the DUE/ARS region eliminates c-myc origin activity (13), and a heterologous DUE restores origin activity, 4 implying that a DUE is essential for chromosomal replication origin activity.In addition to a region of easily unwound DNA, replication origins ...

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Tryptophanyl-tRNA synthetase is found closely associated with and stimulates DNA polymerase α-like activity from wheat embryos

Cited by 18 publications

References 18 publications

Plant DNA polymerases

Plant DNA polymerases

In vivo levels of diadenosine tetraphosphate and adenosine tetraphospho-guanosine in Physarum polycephalum during the cell cycle and oxidative stress.

Structure and Function of the c-myc DNA-unwinding Element-binding Protein DUE-B

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