Enzymes
UniProtKB help_outline | 2 proteins |
Enzyme class help_outline |
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GO Molecular Function help_outline |
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Reaction participants Show >> << Hide
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Namehelp_outline
7-cyano-7-carbaguanosine15 in tRNA
Identifier
RHEA-COMP:10371
Reactive part
help_outline
- Name help_outline 7-cyano-7-carbaguanine 5'-phosphate residue Identifier CHEBI:82850 Charge -1 Formula C12H11N5O7P Positionhelp_outline 15 SMILEShelp_outline Nc1nc2n(cc(C#N)c2c(=O)[nH]1)[C@@H]1O[C@H](COP([O-])(-*)=O)[C@@H](O-*)[C@H]1O 2D coordinates Mol file for the small molecule Search links Involved in 4 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline H2O Identifier CHEBI:15377 (Beilstein: 3587155; CAS: 7732-18-5) help_outline Charge 0 Formula H2O InChIKeyhelp_outline XLYOFNOQVPJJNP-UHFFFAOYSA-N SMILEShelp_outline [H]O[H] 2D coordinates Mol file for the small molecule Search links Involved in 6,204 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline L-glutamine Identifier CHEBI:58359 Charge 0 Formula C5H10N2O3 InChIKeyhelp_outline ZDXPYRJPNDTMRX-VKHMYHEASA-N SMILEShelp_outline NC(=O)CC[C@H]([NH3+])C([O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 75 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
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Namehelp_outline
archaeosine15 in tRNA
Identifier
RHEA-COMP:14170
Reactive part
help_outline
- Name help_outline archaeosine residue Identifier CHEBI:138803 Charge 0 Formula C12H15N6O7P Positionhelp_outline 15 SMILEShelp_outline C1(=O)NC(=NC2=C1C(=CN2[C@@H]3O[C@H](COP(*)([O-])=O)[C@@H](O*)[C@H]3O)C(N)=[NH2+])N 2D coordinates Mol file for the small molecule Search links Involved in 3 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline L-glutamate Identifier CHEBI:29985 (CAS: 11070-68-1) help_outline Charge -1 Formula C5H8NO4 InChIKeyhelp_outline WHUUTDBJXJRKMK-VKHMYHEASA-M SMILEShelp_outline [NH3+][C@@H](CCC([O-])=O)C([O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 244 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
RHEA:54084 | RHEA:54085 | RHEA:54086 | RHEA:54087 | |
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Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
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Publications
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Diversity of archaeosine synthesis in Crenarchaeota.
Phillips G., Swairjo M.A., Gaston K.W., Bailly M., Limbach P.A., Iwata-Reuyl D., de Crecy-Lagard V.
Archaeosine (G(+)) is found at position 15 of many archaeal tRNAs. In Euryarchaeota, the G(+) precursor, 7-cyano-7-deazaguanine (preQ(0)), is inserted into tRNA by tRNA-guanine transglycosylase (arcTGT) before conversion into G(+) by ARChaeosine Synthase (ArcS). However, many Crenarchaeota known t ... >> More
Archaeosine (G(+)) is found at position 15 of many archaeal tRNAs. In Euryarchaeota, the G(+) precursor, 7-cyano-7-deazaguanine (preQ(0)), is inserted into tRNA by tRNA-guanine transglycosylase (arcTGT) before conversion into G(+) by ARChaeosine Synthase (ArcS). However, many Crenarchaeota known to harbor G(+) lack ArcS homologues. Using comparative genomics approaches, two families that could functionally replace ArcS in these organisms were identified: (1) GAT-QueC, a two-domain family with an N-terminal glutamine amidotransferase class-II domain fused to a domain homologous to QueC, the enzyme that produces preQ(0) and (2) QueF-like, a family homologous to the bacterial enzyme catalyzing the reduction of preQ(0) to 7-aminomethyl-7-deazaguanine. Here we show that these two protein families are able to catalyze the formation of G(+) in a heterologous system. Structure and sequence comparisons of crenarchaeal and euryarchaeal arcTGTs suggest the crenarchaeal enzymes have broader substrate specificity. These results led to a new model for the synthesis and salvage of G(+) in Crenarchaeota. << Less
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Discovery and characterization of an amidinotransferase involved in the modification of archaeal tRNA.
Phillips G., Chikwana V.M., Maxwell A., El-Yacoubi B., Swairjo M.A., Iwata-Reuyl D., de Crecy-Lagard V.
The presence of the 7-deazaguanosine derivative archaeosine (G(+)) at position 15 in tRNA is one of the diagnostic molecular characteristics of the Archaea. The biosynthesis of this modified nucleoside is especially complex, involving the initial production of 7-cyano-7-deazaguanine (preQ(0)), an ... >> More
The presence of the 7-deazaguanosine derivative archaeosine (G(+)) at position 15 in tRNA is one of the diagnostic molecular characteristics of the Archaea. The biosynthesis of this modified nucleoside is especially complex, involving the initial production of 7-cyano-7-deazaguanine (preQ(0)), an advanced precursor that is produced in a tRNA-independent portion of the biosynthesis, followed by its insertion into the tRNA by the enzyme tRNA-guanine transglycosylase (arcTGT), which replaces the target guanine base yielding preQ(0)-tRNA. The enzymes responsible for the biosynthesis of preQ(0) were recently identified, but the enzyme(s) catalyzing the conversion of preQ(0)-tRNA to G(+)-tRNA have remained elusive. Using a comparative genomics approach, we identified a protein family implicated in the late stages of archaeosine biosynthesis. Notably, this family is a paralog of arcTGT and is generally annotated as TgtA2. Structure-based alignments comparing arcTGT and TgtA2 reveal that TgtA2 lacks key arcTGT catalytic residues and contains an additional module. We constructed a Haloferax volcanii DeltatgtA2 derivative and demonstrated that tRNA from this strain lacks G(+) and instead accumulates preQ(0). We also cloned the corresponding gene from Methanocaldococcus jannaschii (mj1022) and characterized the purified recombinant enzyme. Recombinant MjTgtA2 was shown to convert preQ(0)-tRNA to G(+)-tRNA using several nitrogen sources and to do so in an ATP-independent process. This is the only example of the conversion of a nitrile to a formamidine known in biology and represents a new class of amidinotransferase chemistry. << Less