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Your query returned 5 entries. Printable version
EC | 1.7.1.13 | ||||||||||||
Accepted name: | preQ1 synthase | ||||||||||||
Reaction: | 7-aminomethyl-7-carbaguanine + 2 NADP+ = 7-cyano-7-carbaguanine + 2 NADPH + 2 H+ | ||||||||||||
For diagram of queuine biosynthesis, click here | |||||||||||||
Glossary: | 7-aminomethyl-7-carbaguanine = preQ1 = 7-aminomethyl-7-deazaguanine 7-cyano-7-carbaguanine = preQ0 = 7-cyano-7-deazaguanine |
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Other name(s): | YkvM; QueF; preQ0 reductase; preQ0 oxidoreductase; 7-cyano-7-deazaguanine reductase; queuine synthase (incorrect as queuine is not the product); queuine:NADP+ oxidoreductase (incorrect as queuine is not the product) | ||||||||||||
Systematic name: | 7-aminomethyl-7-carbaguanine:NADP+ oxidoreductase | ||||||||||||
Comments: | The reaction occurs in the reverse direction. This enzyme catalyses one of the early steps in the synthesis of queuosine (Q-tRNA), and is followed by the action of EC 2.4.2.29, tRNA-guanosine34 transglycosylase. Queuosine is found in the wobble position of tRNAGUN in Eukarya and Bacteria [2] and is thought to be involved in translational modulation. The enzyme is not a GTP cyclohydrolase, as was thought previously based on sequence-homology studies. | ||||||||||||
Links to other databases: | BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 1256460-80-6 | ||||||||||||
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EC | 2.4.2.29 | ||||||||||||
Accepted name: | tRNA-guanosine34 preQ1 transglycosylase | ||||||||||||
Reaction: | guanine34 in tRNA + 7-aminomethyl-7-carbaguanine = 7-aminomethyl-7-carbaguanine34 in tRNA + guanine | ||||||||||||
For diagram of queuine biosynthesis, click here | |||||||||||||
Glossary: | 7-aminomethyl-7-carbaguanine = preQ1 = 7-aminomethyl-7-deazaguanine 7-cyano-7-carbaguanine = preQ0 = 7-cyano-7-deazaguanine |
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Other name(s): | guanine insertion enzyme (ambiguous); tRNA transglycosylase (ambiguous); Q-insertase (ambiguous); transfer ribonucleate glycosyltransferase (ambiguous); tRNA guanine34 transglycosidase (ambiguous); TGT (ambiguous); transfer ribonucleic acid guanine34 transglycosylase (ambiguous) | ||||||||||||
Systematic name: | tRNA-guanosine34:7-aminomethyl-7-deazaguanine tRNA-D-ribosyltransferase | ||||||||||||
Comments: | Certain prokaryotic and eukaryotic tRNAs contain the modified base queuine at position 34. In eubacteria, which produce queuine de novo, the enzyme catalyses the exchange of guanine with the queuine precursor preQ1, which is ultimately modified to queuosine [5]. The enzyme can also use an earlier intermediate, preQ0, to replace guanine in unmodified tRNATyr and tRNAAsn [1]. This enzyme acts after EC 1.7.1.13, preQ1 synthase, in the queuine-biosynthesis pathway. cf. EC 2.4.2.64, tRNA-guanosine34 queuine transglycosylase. | ||||||||||||
Links to other databases: | BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 72162-89-1 | ||||||||||||
References: |
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EC | 2.4.2.48 | ||||||||||||
Accepted name: | tRNA-guanine15 transglycosylase | ||||||||||||
Reaction: | guanine15 in tRNA + 7-cyano-7-carbaguanine = 7-cyano-7-carbaguanine15 in tRNA + guanine | ||||||||||||
Glossary: | 7-cyano-7-carbaguanine = preQ0 = 7-cyano-7-deazaguanine archaeosine = G* = 7-amidino-7-deazaguanosine |
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Other name(s): | tRNA transglycosylase (ambiguous); transfer ribonucleate glycosyltransferase (ambiguous); tRNA guanine15 transglycosidase; TGT (ambiguous); transfer ribonucleic acid guanine15 transglycosylase | ||||||||||||
Systematic name: | tRNA-guanine15:7-cyano-7-carbaguanine tRNA-D-ribosyltransferase | ||||||||||||
Comments: | Archaeal tRNAs contain the modified nucleoside archaeosine at position 15. This archaeal enzyme catalyses the exchange of guanine at position 15 of tRNA with the base preQ0, which is ultimately modified to form the nucleoside archaeosine (cf. EC 2.6.1.97) [1]. | ||||||||||||
Links to other databases: | BRENDA, EXPASY, KEGG, MetaCyc, PDB | ||||||||||||
References: |
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EC | 2.6.1.97 | ||||||||||||
Accepted name: | archaeosine synthase | ||||||||||||
Reaction: | L-glutamine + 7-cyano-7-carbaguanine15 in tRNA + H2O = L-glutamate + archaeine15 in tRNA | ||||||||||||
Glossary: | 7-cyano-7-carbaguanine = preQ0 = 7-cyano-7-deazaguanine archaeine = 7-deaza-7-carbamidoylguanine = base G* archaeosine = G* = 7-amidino-7-deazaguanosine |
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Other name(s): | ArcS; TgtA2; MJ1022 (gene name); glutamine:preQ0-tRNA amidinotransferase (incorrect) | ||||||||||||
Systematic name: | L-glutamine:7-cyano-7-carbaguanine aminotransferase | ||||||||||||
Comments: | In Euryarchaeota the reaction is catalysed by ArcS [1,2]. In Crenarchaeota, which do not have an ArcS homologue, the reaction is catalysed either by a homologue of EC 6.3.4.20, 7-cyano-7-deazaguanine synthase that includes a glutaminase domain (cf. EC 3.5.1.2), or by a homologue of EC 1.7.1.13, preQ1 synthase [2]. The enzyme from the Euryarchaeon Methanocaldococcus jannaschii can also use arginine and ammonium as amino donors. | ||||||||||||
Links to other databases: | BRENDA, EXPASY, KEGG, MetaCyc | ||||||||||||
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EC | 6.3.4.20 | ||||||||||||
Accepted name: | 7-cyano-7-deazaguanine synthase | ||||||||||||
Reaction: | 7-carboxy-7-carbaguanine + NH3 + ATP = 7-cyano-7-carbaguanine + ADP + phosphate + H2O | ||||||||||||
For diagram of queuine biosynthesis, click here | |||||||||||||
Glossary: | preQ0 = 7-cyano-7-carbaguanine = 7-cyano-7-deazaguanine 7-carboxy-7-carbaguanine = 7-carboxy-7-deazaguanine |
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Other name(s): | preQ0 synthase; 7-cyano-7-carbaguanine synthase; queC (gene name) | ||||||||||||
Systematic name: | 7-carboxy-7-carbaguanine:ammonia ligase (ADP-forming) | ||||||||||||
Comments: | Binds Zn2+. The reaction is part of the biosynthesis pathway of queuosine. | ||||||||||||
Links to other databases: | BRENDA, EXPASY, KEGG, MetaCyc, PDB | ||||||||||||
References: |
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