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HAMAP rule MF_03218

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General rule information [?]

PURL https://purl.expasy.org/hamap/rule/MF_03218
Accession MF_03218
Dates 22-JUL-2016 (Created)
13-JUN-2025 (Last updated, Version 16)
Name Q_tRNA_Tgt_euk
Scope(s) Eukaryota
Template(s) Q9BXR0; P28720; P0A847; Q9JMA2; [ Recover all ]
Triggered by
case c? <OC:Eukaryota>
HAMAP; MF_00168 (Get profile general information and statistics)
end case

Propagated annotation [?]

Identifier, protein and gene names [?]

Identifier TGT
Protein name RecName: Full=Queuine tRNA-ribosyltransferase catalytic subunit 1;
                 EC=2.4.2.64;
AltName: Full=Guanine insertion enzyme;
AltName: Full=tRNA-guanine transglycosylase;
case <OC:Vertebrata>
Gene name Name=QTRT1;
else case <OC:Caenorhabditis>
Gene name Name=tgt-1;
end case

Comments [?]

FUNCTIONCatalytic subunit of the queuine tRNA-ribosyltransferase (TGT) that catalyzes the base-exchange of a guanine (G) residue with queuine (Q) at position 34 (anticodon wobble position) in tRNAs with GU(N) anticodons (tRNA-Asp, -Asn, -His and -Tyr), resulting in the hypermodified nucleoside queuosine (7-(((4,5-cis-dihydroxy-2- cyclopenten-1-yl)amino)methyl)-7-deazaguanosine). Catalysis occurs through a double-displacement mechanism. The nucleophile active site attacks the C1' of nucleotide 34 to detach the guanine base from the RNA, forming a covalent enzyme-RNA intermediate. The proton acceptor active site deprotonates the incoming queuine, allowing a nucleophilic attack on the C1' of the ribose to form the product.
CATALYTIC ACTIVITY Reaction=guanosine(34) in tRNA + queuine = queuosine(34) in tRNA + guanine; Xref=Rhea:RHEA:16633, Rhea:RHEA-COMP:10341, Rhea:RHEA- COMP:18571, ChEBI:CHEBI:16235, ChEBI:CHEBI:17433, ChEBI:CHEBI:74269, ChEBI:CHEBI:194431; EC=2.4.2.64;
case <FTGroup:1>
COFACTOR Name=Zn(2+); Xref=ChEBI:CHEBI:29105;
end case
case <OC:Vertebrata>
SUBUNITHeterodimer of a catalytic subunit @gn(QTRT1) and an accessory subunit @gn(QTRT2).
SUBCELLULAR LOCATIONCytoplasm. Mitochondrion outer membrane; Peripheral membrane protein; Cytoplasmic side. Note=Weakly associates with mitochondria, possibly via @gn(QTRT2).
else
SUBUNITHeterodimer of a catalytic subunit and an accessory subunit.
SUBCELLULAR LOCATIONCytoplasm.
end case
SIMILARITYBelongs to the queuine tRNA-ribosyltransferase family.

Keywords [?]

Cytoplasm
case <OC:Vertebrata>
Mitochondrion
Mitochondrion outer membrane
Membrane
end case
Glycosyltransferase
Transferase
tRNA processing
case <FTGroup:1>
Metal-binding
Zinc
end case

Gene Ontology [?]

GO:0005737; Cellular component:cytoplasm
case <OCellular component:Vertebrata>
GO:0005741; Cellular component:mitochondrial outer membrane
end case
GO:0008479; Molecular function:tRNA-guanosine(34) queuine transglycosylase activity
GO:0002099; Biological process:tRNA wobble guanine modification

Cross-references [?]

Pfam PF01702; TGT; 1;
NCBIfam TIGR00430; Q_tRNA_tgt; 1;
NCBIfam TIGR00449; tgt_general; 1;

Features [?]

From: TGT_ZYMMO (P28720)
Key From To Description Tag Condition FTGroup
BINDING 102 106 /ligand="substrate" D-S-G-G-[FY]
REGION 261 267 /note="RNA binding" G-[VIG]-G-x(4)
REGION 285 289 /note="RNA binding; important for wobble base 34 recognition" [TA]-[RK]-x(2)-R
ACT_SITE 102 102 /note="Proton acceptor" D
ACT_SITE 280 280 /note="Nucleophile" D
BINDING 318 318 /ligand="Zn(2+)"
/ligand_id="ChEBI:CHEBI:29105"		 C 1
BINDING 320 320 /ligand="Zn(2+)"
/ligand_id="ChEBI:CHEBI:29105"		 C 1
BINDING 323 323 /ligand="Zn(2+)"
/ligand_id="ChEBI:CHEBI:29105"		 C 1
BINDING 349 349 /ligand="Zn(2+)"
/ligand_id="ChEBI:CHEBI:29105"		 H 1
BINDING 156 156 /ligand="substrate" D
BINDING 203 203 /ligand="substrate" Q
BINDING 230 230 /ligand="substrate" G

Additional information [?]

Size range 396-427 amino acids
Related rules None
Fusion Nter: None Cter: None



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