TGT_BUCAP
ID TGT_BUCAP Reviewed; 368 AA.
AC Q8KA09;
DT 08-NOV-2002, integrated into UniProtKB/Swiss-Prot.
DT 01-OCT-2002, sequence version 1.
DT 03-AUG-2022, entry version 104.
DE RecName: Full=Queuine tRNA-ribosyltransferase {ECO:0000255|HAMAP-Rule:MF_00168};
DE EC=2.4.2.29 {ECO:0000255|HAMAP-Rule:MF_00168};
DE AltName: Full=Guanine insertion enzyme {ECO:0000255|HAMAP-Rule:MF_00168};
DE AltName: Full=tRNA-guanine transglycosylase {ECO:0000255|HAMAP-Rule:MF_00168};
GN Name=tgt {ECO:0000255|HAMAP-Rule:MF_00168}; OrderedLocusNames=BUsg_125;
OS Buchnera aphidicola subsp. Schizaphis graminum (strain Sg).
OC Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC Erwiniaceae; Buchnera.
OX NCBI_TaxID=198804;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=Sg;
RX PubMed=12089438; DOI=10.1126/science.1071278;
RA Tamas I., Klasson L., Canbaeck B., Naeslund A.K., Eriksson A.-S.,
RA Wernegreen J.J., Sandstroem J.P., Moran N.A., Andersson S.G.E.;
RT "50 million years of genomic stasis in endosymbiotic bacteria.";
RL Science 296:2376-2379(2002).
CC -!- FUNCTION: Catalyzes the base-exchange of a guanine (G) residue with the
CC queuine precursor 7-aminomethyl-7-deazaguanine (PreQ1) at position 34
CC (anticodon wobble position) in tRNAs with GU(N) anticodons (tRNA-Asp,
CC -Asn, -His and -Tyr). Catalysis occurs through a double-displacement
CC mechanism. The nucleophile active site attacks the C1' of nucleotide 34
CC to detach the guanine base from the RNA, forming a covalent enzyme-RNA
CC intermediate. The proton acceptor active site deprotonates the incoming
CC PreQ1, allowing a nucleophilic attack on the C1' of the ribose to form
CC the product. After dissociation, two additional enzymatic reactions on
CC the tRNA convert PreQ1 to queuine (Q), resulting in the hypermodified
CC nucleoside queuosine (7-(((4,5-cis-dihydroxy-2-cyclopenten-1-
CC yl)amino)methyl)-7-deazaguanosine). {ECO:0000255|HAMAP-Rule:MF_00168}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=7-aminomethyl-7-carbaguanine + guanosine(34) in tRNA = 7-
CC aminomethyl-7-carbaguanosine(34) in tRNA + guanine;
CC Xref=Rhea:RHEA:24104, Rhea:RHEA-COMP:10341, Rhea:RHEA-COMP:10342,
CC ChEBI:CHEBI:16235, ChEBI:CHEBI:58703, ChEBI:CHEBI:74269,
CC ChEBI:CHEBI:82833; EC=2.4.2.29; Evidence={ECO:0000255|HAMAP-
CC Rule:MF_00168};
CC -!- COFACTOR:
CC Name=Zn(2+); Xref=ChEBI:CHEBI:29105;
CC Evidence={ECO:0000255|HAMAP-Rule:MF_00168};
CC Note=Binds 1 zinc ion per subunit. {ECO:0000255|HAMAP-Rule:MF_00168};
CC -!- PATHWAY: tRNA modification; tRNA-queuosine biosynthesis.
CC {ECO:0000255|HAMAP-Rule:MF_00168}.
CC -!- SUBUNIT: Homodimer. Within each dimer, one monomer is responsible for
CC RNA recognition and catalysis, while the other monomer binds to the
CC replacement base PreQ1. {ECO:0000255|HAMAP-Rule:MF_00168}.
CC -!- SIMILARITY: Belongs to the queuine tRNA-ribosyltransferase family.
CC {ECO:0000255|HAMAP-Rule:MF_00168}.
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DR EMBL; AE013218; AAM67693.1; -; Genomic_DNA.
DR RefSeq; WP_011053660.1; NC_004061.1.
DR AlphaFoldDB; Q8KA09; -.
DR SMR; Q8KA09; -.
DR STRING; 198804.BUsg_125; -.
DR EnsemblBacteria; AAM67693; AAM67693; BUsg_125.
DR KEGG; bas:BUsg_125; -.
DR eggNOG; COG0343; Bacteria.
DR HOGENOM; CLU_022060_0_1_6; -.
DR OMA; GIDLFDC; -.
DR OrthoDB; 1165356at2; -.
DR UniPathway; UPA00392; -.
DR Proteomes; UP000000416; Chromosome.
DR GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR GO; GO:0008479; F:queuine tRNA-ribosyltransferase activity; IEA:UniProtKB-UniRule.
DR GO; GO:0008616; P:queuosine biosynthetic process; IEA:UniProtKB-UniRule.
DR GO; GO:0101030; P:tRNA-guanine transglycosylation; IEA:InterPro.
DR Gene3D; 3.20.20.105; -; 1.
DR HAMAP; MF_00168; Q_tRNA_Tgt; 1.
DR InterPro; IPR004803; TGT.
DR InterPro; IPR036511; TGT-like_sf.
DR InterPro; IPR002616; tRNA_ribo_trans-like.
DR Pfam; PF01702; TGT; 1.
DR SUPFAM; SSF51713; SSF51713; 1.
DR TIGRFAMs; TIGR00430; Q_tRNA_tgt; 1.
DR TIGRFAMs; TIGR00449; tgt_general; 1.
PE 3: Inferred from homology;
KW Glycosyltransferase; Metal-binding; Queuosine biosynthesis; Transferase;
KW tRNA processing; Zinc.
FT CHAIN 1..368
FT /note="Queuine tRNA-ribosyltransferase"
FT /id="PRO_0000135458"
FT REGION 247..253
FT /note="RNA binding"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00168"
FT REGION 271..275
FT /note="RNA binding; important for wobble base 34
FT recognition"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00168"
FT ACT_SITE 89
FT /note="Proton acceptor"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00168"
FT ACT_SITE 266
FT /note="Nucleophile"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00168"
FT BINDING 89..93
FT /ligand="substrate"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00168"
FT BINDING 143
FT /ligand="substrate"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00168"
FT BINDING 216
FT /ligand="substrate"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00168"
FT BINDING 304
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00168"
FT BINDING 306
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00168"
FT BINDING 309
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00168"
FT BINDING 335
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00168"
SQ SEQUENCE 368 AA; 42578 MW; 2D6F976063DBD764 CRC64;
MKFQVISQDK EARHGMFNFN GNIIETPVFM PVGTYGTVKS LNIEEIKNTG SKIILSNALH
LYLRPGQDII KLHGSLHNFM NWNGPILTDS GGFQIFSLSN FCRIKEEGVI FKNHINGKKF
FLTPELSMEI QIDLGSNIIM IFDECIAYNK DWEKTKFAME RSLNWSRRSR IHFDLKKKNK
KNLLFGIIHG GSYKSLRDIS LKELIKMDFD GYALGGLAVG ESKLEMHDLL DHITPQIPKK
KPRYLMGVGK PEDLIESVYR GIDMFDCVLP TRNARNGHLF VTNGIIKIRN AKYKKDLSVL
DKKCTCYTCQ NYSRSYLHHL DSCNEILGAR LNTIHNLHYY QTLMFNIRNA IKQKKFDEFV
SNFYNQKK
