The structure of Q* nucleoside isolated from rabbit liver transfer ribonucleic acid

Kasai, Hiroshi; Nakanishi, Koji; Macfarlane, Ronald D.; Torgerson, D F; Ohashi, Ziro; McCloskey, J A; Groß, H.; Nishimura, Susumu

doi:10.1021/ja00432a071

Cited by 132 publications

(77 citation statements)

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“…5B) (31) presents both a possible functional amino group and a cyclopentene moiety bearing vicinal cis diols. These hydroxyl groups are reactive, as some mammalian tRNAs contain modified versions of queuosine in which the 5-hydroxyl is mannosylated or galactosylated (32). To determine whether queuosine is the ''acceptor'' for glutamate, we prepared tRNA from an E. coli mutant strain deficient in the first step of queuosine formation (13).…”

Section: Pure E Coli Trna Asp Can Be Acylated With Aspartate and Glumentioning

confidence: 99%

A truncated aminoacyl–tRNA synthetase modifies RNA

Salazar

Ambrogelly

Crain

et al. 2004

Proc. Natl. Acad. Sci. U.S.A.

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Aminoacyl-tRNA synthetases are modular enzymes composed of a central active site domain to which additional functional domains were appended in the course of evolution. Analysis of bacterial genome sequences revealed the presence of many shorter aminoacyl-tRNA synthetase paralogs. Here we report the characterization of a well conserved glutamyl-tRNA synthetase (GluRS) paralog (YadB in Escherichia coli) that is present in the genomes of >40 species of proteobacteria, cyanobacteria, and actinobacteria. The E. coli yadB gene encodes a truncated GluRS that lacks the C-terminal third of the protein and, consequently, the anticodon binding domain. Generation of a yadB disruption showed the gene to be dispensable for E. coli growth in rich and minimal media. Unlike GluRS, the YadB protein was able to activate glutamate in presence of ATP in a tRNA-independent fashion and to transfer glutamate onto tRNA Asp . Neither tRNA Glu nor tRNA Gln were substrates. In contrast to canonical aminoacyl-tRNA, glutamate was not esterified to the 3 -terminal adenosine of tRNA Asp . Instead, it was attached to the 2-amino-5-(4,5-dihydroxy-2-cyclopenten-1-yl) moiety of queuosine, the modified nucleoside occupying the first anticodon position of tRNA Asp . Glutamyl-queuosine, like canonical Glu-tRNA, was hydrolyzed by mild alkaline treatment. Analysis of tRNA isolated under acidic conditions showed that this novel modification is present in normal E. coli tRNA; presumably it previously escaped detection as the standard conditions of tRNA isolation include an alkaline deacylation step that also causes hydrolysis of glutamyl-queuosine. Thus, this aminoacyl-tRNA synthetase fragment contributes to standard nucleotide modification of tRNA.

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Section: Pure E Coli Trna Asp Can Be Acylated With Aspartate and Glumentioning

confidence: 99%

A truncated aminoacyl–tRNA synthetase modifies RNA

Salazar

Ambrogelly

Crain

et al. 2004

Proc. Natl. Acad. Sci. U.S.A.

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“…The cluster of ions around mlz 656 (Fig. 3B) arises from the cleavage below the secondary amine of the side chain and is highly characteristic of Q nucleoside (19). The ion at mlz 614 is the C12F24N ion of perfluorotributylamine included as an internal standard for mass reference in all EI MS experiments.…”

Section: Q Salvage and Lack Of Synthesis In Eucaryotic Algae 5637mentioning

confidence: 99%

Novel salvage of queuine from queuosine and absence of queuine synthesis in Chlorella pyrenoidosa and Chlamydomonas reinhardtii

et al. 1988

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Partially purified extracts from Chlorella pyrenoidosa and Chlamydomonas reinhardtii catalyze the cleavage of queuosine (Q), a modified 7-deazaguanine nucleoside found exclusively in the first position of the anticodon of certain tRNAs, to queuine, the base of Q. This is the first report of an enzyme that specifically cleaves a 7.deazapurine riboside. Guanosine is not a substrate for this activity, nor is the epoxide a derivative of Q. We also establish that both algae can incorporate exogenously supplied queuine into their tRNA but lack Q-containing tRNA when cultivated in the absence of queuine, indicating that they are unable to synthesize Q de novo. Although no physiological function for Q has been identified in these algae, Q cleavage to queuine would enable algae to generate queuine from exogenous Q in the wild and also to salvage (and recycle) queuine from intracellular tRNA degraded during the normal turnover process. In mammalian cells, queuine salvage occurs by the specific cleavage of queuine from Q-5'-phosphate. The present data also support the hypothesis that plants, like animals, cannot synthesize Q de novo.The modified nucleoside 7-{5-[(4,5-dihydroxy-2-cyclopent-1-yl)amino]methyl}-7-deaza-guanosine, queuosine (Q), and its glycosylated derivatives (Q*) are found in the first position of the anticodons for tRNAs accommodating the amino acids asparagine, aspartic acid, histidine, and tyrosine (reviewed in reference 25). Q is widely distributed in the biosphere, occurring in the tRNA of plants, animals, and eubacteria (25). Bacteria synthesize Q de novo by the irreversible, base-for-base exchange of 7-aminomethyl-7-deazaguanine for guanine in position 34 of the tRNA, after which the cyclopentenediol moiety is added in an unknown fashion (25). The base exchange is catalyzed by tRNAguanine ribosyltransferase (25). Eucaryotes synthesize Q similarly, with the exception that queuine, the base of Q, is exchanged for the guanine in position 34 (22,23,25,31). Animals do not synthesize Q de novo and must obtain queuine from the diet or gut flora, either as the free base or, after degradation of Q-containing (Q+) tRNA, by the specific cleavage of Q-5'-phosphate (Q-5'-P) to queuine (12,18,21,28). It is notable that queuine is not a substrate for Escherichia coli tRNA-guanine ribosyltransferase (25).Animal serum provides queuine to mammalian cells in tissue culture, and this has been exploited to develop a sensitive bioassay for queuine: in the mouse cell line L-M, which is propagated in a serum-free medium, the Q content of tRNA is directly related to the concentration of queuine added to the medium (21, 22). The L-M cell assay has enabled the detection of significant amounts of free queuine in plant and animal products common to the human diet (21). * Corresponding author. Whether plants synthesize queuine de novo or obtain it from exogenous sources has not been established.The present study was prompted by the discovery that extracts from Chlorella pyrenoidosa, which had been cultivated in a defined queuine-f...

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“…In some instances the lipid moiety has been identified as dolichol (8), and there in also evidence that retinol is involved as a lipid intermediate (9). In contrast to the synthesis of these glycoproteins, no lipid intermediate seems to be involved in the biosynthesis of manQ: namely, the mannosyltransferase reported here can be isolated from 105,000 x g supernatant that is free from a particulate fraction, and it can be purified further by DEAE-cellulose column chromatography, Additional evidence to support the conclusion that there is no lipid intermediate is that the mannosyl residue in manQ is attached to cyclopentene diol in the 0 form (3). The mannose moiety is probably incorporated into cyclopentene diol in the same configuration in the cell-free system reported here, since an inversion of the anomeric configuration of D-mannose is known to occur in the transfer of the sugar from GDP-D-a-mannose (8).…”

Section: Resultsmentioning

confidence: 51%

Enzymatic synthesis of Q^*nucleoside containing mannose in the anticodon of tRNA: isolation of a novel mannosyltransferase from a cell-free extract of rat liver

Okada¹,

Nishimura²

1977

Nucl Acids Res

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The Q* nucleosides isolated from rabbit liver tRNA are known to have sugars (mannose or galactose) linked to their cyclopentene diol moiety.A Q^nucleoside containing mannose (manQ) was synthesized by a cell-free system from rat liver, using purified E. coZi tRNAASP as an acceptor and GDP-mannose as a donor molecule. The novel mannosyltransferase catalyzing this reaction was purified from a particulate-free soluble enzyme fraction and found to be strictly specific for tRNAAsP. These results, together with the anomeric configuration of mannose in Q* nucleoside, indicate that no lipid intermediate is involved in the biosynthesis of Q* nucleoside.

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The structure of Q* nucleoside isolated from rabbit liver transfer ribonucleic acid

Cited by 132 publications

References 1 publication

A truncated aminoacyl–tRNA synthetase modifies RNA

A truncated aminoacyl–tRNA synthetase modifies RNA

Novel salvage of queuine from queuosine and absence of queuine synthesis in Chlorella pyrenoidosa and Chlamydomonas reinhardtii

Enzymatic synthesis of Q^*nucleoside containing mannose in the anticodon of tRNA: isolation of a novel mannosyltransferase from a cell-free extract of rat liver

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The structure of Q* nucleoside isolated from rabbit liver transfer ribonucleic acid

Cited by 132 publications

References 1 publication

A truncated aminoacyl–tRNA synthetase modifies RNA

A truncated aminoacyl–tRNA synthetase modifies RNA

Novel salvage of queuine from queuosine and absence of queuine synthesis in Chlorella pyrenoidosa and Chlamydomonas reinhardtii

Enzymatic synthesis of Q*nucleoside containing mannose in the anticodon of tRNA: isolation of a novel mannosyltransferase from a cell-free extract of rat liver

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Enzymatic synthesis of Q^*nucleoside containing mannose in the anticodon of tRNA: isolation of a novel mannosyltransferase from a cell-free extract of rat liver