14 results match your criteria mnme mnmg

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Absolute requirement for polyamines for growth of Escherichia coli mutants (mnmE/G) defective in modification of the wobble anticodon of transfer-RNA.

FEMS Microbiol Lett 2019 05;366(10)

Laboratory of Biochemistry and Genetics, NIDDK, National Institutes of Health, Bethesda, Maryland, USA 20892-0830.

The genes mnmE and mnmG are responsible for the modification of uridine 34, 'the wobble position' of many aminoacyl-tRNAs. Deletion of these genes affects the strength of the codon-anticodon interactions of the aminoacyl-tRNAs with the mRNAs and the ribosomes. However, deletion of these genes does not usually have a significant effect on the growth rate of the standard Escherichia coli strains. Read More

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Bacillus subtilis exhibits MnmC-like tRNA modification activities.

RNA Biol 2018 24;15(9):1167-1173. Epub 2018 Sep 24.

a Laboratory of RNA Modification and Mitochondrial Diseases , Centro de Investigación Príncipe Felipe , Valencia , Spain.

The MnmE-MnmG complex of Escherichia coli uses either ammonium or glycine as a substrate to incorporate the 5-aminomethyl or 5-carboxymethylaminomethyl group into the wobble uridine of certain tRNAs. Both modifications can be converted into a 5-methylaminomethyl group by the independent oxidoreductase and methyltransferase activities of MnmC, which respectively reside in the MnmC(o) and MnmC(m) domains of this bifunctional enzyme. MnmE and MnmG, but not MnmC, are evolutionarily conserved. Read More

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December 2018

An Alternative Homodimerization Interface of MnmG Reveals a Conformational Dynamics that Is Essential for Its tRNA Modification Function.

J Mol Biol 2018 08 2;430(17):2822-2842. Epub 2018 Jun 2.

Centro de Investigación Príncipe Felipe, Valencia 46012, Spain; Biomedical Research Networking Centre for Rare Diseases (CIBERER, Node 721), Valencia, Spain. Electronic address:

The Escherichia coli homodimeric proteins MnmE and MnmG form a functional complex, MnmEG, that modifies tRNAs using GTP, methylene-tetrahydrofolate, FAD, and glycine or ammonium. MnmE is a tetrahydrofolate- and GTP-binding protein, whereas MnmG is a FAD-binding protein with each protomer composed of the FAD-binding domain, two insertion domains, and the helical C-terminal domain. The detailed mechanism of the MnmEG-mediated reaction remains unclear partially due to incomplete structural information on the free- and substrate-bound forms of the complex. Read More

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Invited review: MnmE, a GTPase that drives a complex tRNA modification reaction.

Biopolymers 2016 Aug;105(8):568-79

Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, Brussel, 1050, Belgium.

MnmE is a multi-domain GTPase that is conserved from bacteria to man. Together with its partner protein MnmG it is involved in the synthesis of a tRNA wobble uridine modification. The orthologues of these proteins in eukaryotes are targeted to mitochondria and mutations in the encoding genes are associated with severe mitochondrial diseases. Read More

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Functions that protect Escherichia coli from DNA-protein crosslinks.

DNA Repair (Amst) 2015 Apr 7;28:48-59. Epub 2015 Feb 7.

Department of Biochemistry, Duke University Medical Center, Durham NC 27710, United States. Electronic address:

Pathways for tolerating and repairing DNA-protein crosslinks (DPCs) are poorly defined. We used transposon mutagenesis and candidate gene approaches to identify DPC-hypersensitive Escherichia coli mutants. DPCs were induced by azacytidine (aza-C) treatment in cells overexpressing cytosine methyltransferase; hypersensitivity was verified to depend on methyltransferase expression. Read More

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Modification of the wobble uridine in bacterial and mitochondrial tRNAs reading NNA/NNG triplets of 2-codon boxes.

RNA Biol 2014 ;11(12):1495-507

a Laboratory of RNA Modification and Mitochondrial Diseases ; Centro de Investigación Príncipe Felipe ; Valencia , Spain.

Posttranscriptional modification of the uridine located at the wobble position (U34) of tRNAs is crucial for optimization of translation. Defects in the U34 modification of mitochondrial-tRNAs are associated with a group of rare diseases collectively characterized by the impairment of the oxidative phosphorylation system. Retrograde signaling pathways from mitochondria to nucleus are involved in the pathophysiology of these diseases. Read More

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October 2015

SAXS analysis of the tRNA-modifying enzyme complex MnmE/MnmG reveals a novel interaction mode and GTP-induced oligomerization.

Nucleic Acids Res 2014 May 14;42(9):5978-92. Epub 2014 Mar 14.

Structural Biology Research Center, VIB, Pleinlaan 2, 1050 Brussel, Belgium Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium

Transfer ribonucleic acid (tRNA) modifications, especially at the wobble position, are crucial for proper and efficient protein translation. MnmE and MnmG form a protein complex that is implicated in the carboxymethylaminomethyl modification of wobble uridine (cmnm(5)U34) of certain tRNAs. MnmE is a G protein activated by dimerization (GAD), and active guanosine-5'-triphosphate (GTP) hydrolysis is required for the tRNA modification to occur. Read More

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The output of the tRNA modification pathways controlled by the Escherichia coli MnmEG and MnmC enzymes depends on the growth conditions and the tRNA species.

Nucleic Acids Res 2014 Feb 30;42(4):2602-23. Epub 2013 Nov 30.

Laboratory of RNA Modification and Mitochondrial Diseases, Príncipe Felipe Research Center, 46012-Valencia, Spain, Department of Molecular Biology, Umeå University, S90187, Sweden and Biomedical Research Networking Centre for Rare Diseases (CIBERER) (node U721), Spain.

In Escherichia coli, the MnmEG complex modifies transfer RNAs (tRNAs) decoding NNA/NNG codons. MnmEG catalyzes two different modification reactions, which add an aminomethyl (nm) or carboxymethylaminomethyl (cmnm) group to position 5 of the anticodon wobble uridine using ammonium or glycine, respectively. In tRNA(cmnm5s2UUG)(Gln) and tRNA(cmnm5UmAA)(Leu), however, cmnm(5) appears as the final modification, whereas in the remaining tRNAs, the MnmEG products are converted into 5-methylaminomethyl (mnm(5)) through the two-domain, bi-functional enzyme MnmC. Read More

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February 2014

Characterization and structure of the Aquifex aeolicus protein DUF752: a bacterial tRNA-methyltransferase (MnmC2) functioning without the usually fused oxidase domain (MnmC1).

J Biol Chem 2012 Dec 22;287(52):43950-60. Epub 2012 Oct 22.

RIKEN SPring-8 Center, Harima Institute, 1-1-1 Kouto, Sayo, Hyogo 679-5148, Japan.

Post-transcriptional modifications of the wobble uridine (U34) of tRNAs play a critical role in reading NNA/G codons belonging to split codon boxes. In a subset of Escherichia coli tRNA, this wobble uridine is modified to 5-methylaminomethyluridine (mnm(5)U34) through sequential enzymatic reactions. Uridine 34 is first converted to 5-carboxymethylaminomethyluridine (cmnm(5)U34) by the MnmE-MnmG enzyme complex. Read More

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December 2012

Enzymology of tRNA modification in the bacterial MnmEG pathway.

Biochimie 2012 Jul 28;94(7):1510-20. Epub 2012 Feb 28.

Laboratorio de Genética Molecular, Centro de Investigación Príncipe Felipe, Molecular Genetics, Avenida Autopista del Saler, 16-3, 46012-Valencia, Spain.

Among all RNAs, tRNA exhibits the largest number and the widest variety of post-transcriptional modifications. Modifications within the anticodon stem loop, mainly at the wobble position and purine-37, collectively contribute to stabilize the codon-anticodon pairing, maintain the translational reading frame, facilitate the engagement of the ribosomal decoding site and enable translocation of tRNA from the A-site to the P-site of the ribosome. Modifications at the wobble uridine (U34) of tRNAs reading two degenerate codons ending in purine are complex and result from the activity of two multi-enzyme pathways, the IscS-MnmA and MnmEG pathways, which independently work on positions 2 and 5 of the U34 pyrimidine ring, respectively, and from a third pathway, controlled by TrmL (YibK), that modifies the 2'-hydroxyl group of the ribose. Read More

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Evidence that the folate-dependent proteins YgfZ and MnmEG have opposing effects on growth and on activity of the iron-sulfur enzyme MiaB.

J Bacteriol 2012 Jan 11;194(2):362-7. Epub 2011 Nov 11.

Plant Molecular and Cellular Biology Program, University of Florida, Gainesville, Florida, USA.

The folate-dependent protein YgfZ of Escherichia coli participates in the synthesis and repair of iron-sulfur (Fe-S) clusters; it belongs to a family of enzymes that use folate to capture formaldehyde units. Ablation of ygfZ is known to reduce growth, to increase sensitivity to oxidative stress, and to lower the activities of MiaB and other Fe-S enzymes. It has been reported that the growth phenotype can be suppressed by disrupting the tRNA modification gene mnmE. Read More

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January 2012

Stabilization of G domain conformations in the tRNA-modifying MnmE-GidA complex observed with double electron electron resonance spectroscopy.

J Biol Chem 2010 May 30;285(22):16991-7000. Epub 2010 Mar 30.

Department of Physics, University of Osnabrück, Barbarastrasse 7, D-49076 Osnabrück, Germany.

MnmE is a GTP-binding protein conserved between bacteria and eukarya. It is a dimeric three-domain protein where the two G domains have to approach each other for activation of the potassium-stimulated GTPase reaction. Together with GidA, in a heterotetrameric alpha(2)beta(2) complex, it is involved in the modification of the wobble uridine base U34 of the first anticodon position of particular tRNAs. Read More

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Structure-function analysis of Escherichia coli MnmG (GidA), a highly conserved tRNA-modifying enzyme.

J Bacteriol 2009 Dec 2;191(24):7614-9. Epub 2009 Oct 2.

Department of Biochemistry, McGill University, Montreal, Quebec, Canada.

The MnmE-MnmG complex is involved in tRNA modification. We have determined the crystal structure of Escherichia coli MnmG at 2.4-A resolution, mutated highly conserved residues with putative roles in flavin adenine dinucleotide (FAD) or tRNA binding and MnmE interaction, and analyzed the effects of these mutations in vivo and in vitro. Read More

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December 2009

Evolutionarily conserved proteins MnmE and GidA catalyze the formation of two methyluridine derivatives at tRNA wobble positions.

Nucleic Acids Res 2009 Nov;37(21):7177-93

Laboratorio de Genética Molecular, Centro de Investigación Príncipe Felipe, 46012-Valencia, Spain.

The wobble uridine of certain bacterial and mitochondrial tRNAs is modified, at position 5, through an unknown reaction pathway that utilizes the evolutionarily conserved MnmE and GidA proteins. The resulting modification (a methyluridine derivative) plays a critical role in decoding NNG/A codons and reading frame maintenance during mRNA translation. The lack of this tRNA modification produces a pleiotropic phenotype in bacteria and has been associated with mitochondrial encephalomyopathies in humans. Read More

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November 2009
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