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Annotation rule MF_03218
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General rule information [?]

Accession MF_03218
Dates 22-JUL-2016 (Created)
20-NOV-2019 (Last updated, Version 6)
Name Q_tRNA_Tgt_euk
Scope
Eukaryota
Templates Q9BXR0 (TGT_HUMAN); P28720 (TGT_ZYMMO); P0A847 (TGT_ECOLI); Q9JMA2 (TGT_MOUSE): [Recover all]
case <OC:Eukaryota>
Triggered by
end case


Propagated annotation [?]


Identifier, protein and gene names [?]

Identifier
TGT
Protein name
RecName: Full=Queuine tRNA-ribosyltransferase catalytic subunit 1;
EC 2.4.2.29;
AltName: Full=Guanine insertion enzyme;
AltName: Full=tRNA-guanine transglycosylase;
case <OC:Vertebrata>
Gene name
QTRT1
else case <OC:Caenorhabditis>
Gene name
tgt-1
end case

Comments [?]

Function Catalytic 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 RHEA:16633: guanosine(34) in tRNA + queuine = guanine + queuosine(34) in tRNA
EC 2.4.2.29
case <FTGroup:1>
Cofactor Zn(2+)
end case
case <OC:Vertebrata>
Subunit Heterodimer of a catalytic subunit @gn(QTRT1) and an accessory subunit @gn(QTRT2).
Subcellular location Cytoplasm. Mitochondrion outer membrane; Peripheral membrane protein; Cytoplasmic side. Note=Weakly associates with mitochondria, possibly via @gn(QTRT2).
else
Subunit Heterodimer of a catalytic subunit and an accessory subunit.
Subcellular location Cytoplasm.
end case
Similarity Belongs 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 <OC:Vertebrata>
GO:0005741; Cellular component: mitochondrial outer membrane.
end case
GO:0008479; Molecular function: queuine tRNA-ribosyltransferase activity.
GO:0101030; Biological process: tRNA-guanine transglycosylation.

Cross-references [?]

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

Features [?]

From: TGT_ZYMMO (P28720)
Key     From     To       Description   Tag   Condition   FTGroup
REGION     102     106       Substrate binding     D-S-G-G-[FY]  
REGION     261     267       RNA binding     G-[VIG]-G-x(4)  
REGION     285     289       RNA binding; important for wobble base 34 recognition     [TA]-[RK]-x(2)-R  
ACT_SITE     102     102       Proton acceptor     D  
ACT_SITE     280     280       Nucleophile     D  
METAL     318     318       Zinc     C   1
METAL     320     320       Zinc     C   1
METAL     323     323       Zinc     C   1
METAL     349     349       Zinc; via pros nitrogen     H   1
BINDING     156     156       Substrate     D  
BINDING     203     203       Substrate     Q  
BINDING     230     230       Substrate; via amide nitrogen     G  

Additional information [?]

Size range 396-427 amino acids
Related rules None
Fusion None


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