HOME
login
history
all enzymes
BRENDA home
History
Enzyme Nomenclature
Information on EC 6.3.4.20 - 7-cyano-7-deazaguanine synthase
for references in articles please use BRENDA:EC6.3.4.20Please wait a moment until all data is loaded. This message will disappear when all data is loaded.
Specify your search results
The expected taxonomic range for this enzyme is: Bacteria, Archaea
topPlease wait a moment until the data is sorted. This message will disappear when the data is sorted.
EC NUMBER 
COMMENTARY 
6.3.4.20
-
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
RECOMMENDED NAME
GeneOntology No.
7-cyano-7-deazaguanine synthase
-
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
REACTION
REACTION DIAGRAM
COMMENTARY
ORGANISM
UNIPROT
LITERATURE
7-carboxy-7-carbaguanine + NH3 + ATP = 7-cyano-7-carbaguanine + ADP + phosphate + H2O
-
-
-
-
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
PATHWAY
BRENDA Link
KEGG Link
MetaCyc Link
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
SYSTEMATIC NAME
IUBMB Comments
7-carboxy-7-carbaguanine:ammonia ligase (ADP-forming)
Binds Zn2+. The reaction is part of the biosynthesis pathway of queuosine.
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
CAS REGISTRY NUMBER
COMMENTARY
1256460-80-6
-
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
ORGANISM
COMMENTARY
LITERATURE
UNIPROT
SEQUENCE DB
SOURCE
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
GENERAL INFORMATION
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
evolution
-
the enzyme belongs to 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 preQ0. Phylogenetic distribution of aTGT, ArcS, GAT-QueC, and QueF-like in the two archaeal phyla, overview. Most crenarchaeal genomes encode a fused GAT-QueC protein or a QueF-like protein
malfunction
-
the expression of QueC from a plasmid-borne copy confers a Q+ phenotype to enzyme-deficient mutant strain Escherichia coli B105
metabolism
physiological function
metabolism
-
the metabolic pathway includes the conversion of the biosynthetic intermediate, 6-carboxy-5,6,7,8-tetrahydropterin, to intermediate, 7-carboxy-7-deazaguanine, CDG, by an unusual transformation catalyzed by QueE, a member of the radical SAM enzyme superfamily. The carboxylate moiety on CDG is converted subsequently to a nitrile to yield preQ0 by QueC in an ATP-dependent reaction, in which ammonia serves as the nitrogen source. CDG may be the central precursor to all deazapurines, biosynthesis of deazapurine containing compounds in nature incorporates H2NTP, CPH4 and CDG as common intermediates
metabolism
-
the queC (ybaX) gene product functions in the initial step of queuosine biosynthetic pathway in Escherichia coli, queuosine incorporation in tRNAs, overview
metabolism
the products of four genes, queC, queD, queE, and queF, are involved in preQ1 biosynthesis with GTP as the starting material. preQ1 is transformed to Q in tRNA
physiological function
-
the enzyme QueC produces the G+ precursor, 7-cyano-7-deazaguanine, i.e. preQ0, which is inserted into tRNA by tRNA-guanine transglycosylase before conversion into G+ by archaeosine synthase, ArcS. Gat-QueC and QueF-like families can compensate for lack of ArcS, overview
physiological function
-
involvement of QueC at a step leading to production of preQ0, intermediate in the pathway that utilizes GTP as the starting molecule to produce queuosine, overview
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
SUBSTRATE
PRODUCT
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate)
(Substrate)
LITERATURE
(Substrate)
(Substrate)
COMMENTARY
(Product)
(Product)
LITERATURE
(Product)
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
r=reversible
ir=irreversible
?=not specified
7-carboxy-7-carbaguanine + NH3 + ATP
7-cyano-7-carbaguanine + ADP + phosphate + H2O
-
-
-
-
?
7-carboxy-7-carbaguanine + NH3 + ATP
7-cyano-7-carbaguanine + ADP + phosphate + H2O
-
dependent conversion of a carboxylic acid to a nitrile
-
-
?
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
NATURAL SUBSTRATES
NATURAL PRODUCTS
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate)
(Substrate)
LITERATURE
(Substrate)
(Substrate)
COMMENTARY
(Product)
(Product)
LITERATURE
(Product)
(Product)
REVERSIBILITY
r=reversible
ir=irreversible
?=not specified
r=reversible
ir=irreversible
?=not specified
7-carboxy-7-carbaguanine + NH3 + ATP
7-cyano-7-carbaguanine + ADP + phosphate + H2O
-
-
-
-
?
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
COFACTOR
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
METALS and IONS
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
Zn2+
coordination of a zinc ion by the conserved C(x)8CxxCxxC motif in QueC, binding structure, overview
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
pH OPTIMUM
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
pI VALUE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
SUBUNITS
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
dimer or tetramer
the biologically relevant unit is likely to be a QueC homodimer, crystal structure. Monomer structure, overview. The Rossmann fold of the N-terminal part of QueC, in combination with the C-terminal zinc-binding motif, forms a cavity in QueC of substantial size, which is likely to be the location of substrate binding
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
Crystallization/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
purified QueC, vapor diffusion method, 10 mg/ml protein is mixed with crystallization solution containing 25% PEG 6000, 100 mM NaCl, 10 mM 1,6 hexanediol, and 100 mM MES, pH 5.5, 1 week, X-ray diffraction structure determination and analysis at 2.95 A resolution
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
Purification/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
recombinant His-tagged QueC from Escherichia coli strain BL21(DE3) by nickel affinity chromatography and gel filtration
-
recombinant QueC from Escherichia coli strain BL21(DE3) by anion exchange chromatography, hydrophobic interaction chromatography, and another different step of anion exchange chromatography, followed by gel filtration
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
Cloned/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
cloning of His-tagged QueC and expression in Escherichia coli strain BL21(DE3)
-
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
ENGINEERING
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
additional information
additional information
-
in vitro preparation of the deazapurine nucleoside, preQ0, by the successive action of the four involved enzymes, i.e. Escherichia coli QueD, Bacillus subtilis QueE and QueC, and Streptomyces rimosus ToyM, cloning and expression in Escherichia coli strain BL21(DE3), overview
additional information
-
the expression of QueC from a plasmid-borne copy confers a Q+ phenotype to enzyme-deficient mutant strain Escherichia coli B105, mapping of the transposon insertion site, overview. Generation of a knockout of queC in Escherichia coli strain JE10651, a queA mutant
Show AA Sequence (12769 entries)
Longer loading times are possible. Please use the Sequence Search for a specific query.
Longer loading times are possible. Please use the Sequence Search for a specific query.
Please wait a moment until the data is sorted. This message will disappear when the data is sorted.
LINKS TO OTHER DATABASES (specific for EC-Number 6.3.4.20)
html completed
Use of this online version of BRENDA is free but requires a license. See terms of use.
Information
