TGT_ACIBT
ID TGT_ACIBT Reviewed; 377 AA.
AC A3M8S3;
DT 24-MAR-2009, integrated into UniProtKB/Swiss-Prot.
DT 02-SEP-2008, sequence version 2.
DT 03-AUG-2022, entry version 89.
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=A1S_2912;
OS Acinetobacter baumannii (strain ATCC 17978 / CIP 53.77 / LMG 1025 / NCDC
OS KC755 / 5377).
OC Bacteria; Proteobacteria; Gammaproteobacteria; Moraxellales; Moraxellaceae;
OC Acinetobacter; Acinetobacter calcoaceticus/baumannii complex.
OX NCBI_TaxID=400667;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=ATCC 17978 / CIP 53.77 / LMG 1025 / NCDC KC755 / 5377;
RX PubMed=17344419; DOI=10.1101/gad.1510307;
RA Smith M.G., Gianoulis T.A., Pukatzki S., Mekalanos J.J., Ornston L.N.,
RA Gerstein M., Snyder M.;
RT "New insights into Acinetobacter baumannii pathogenesis revealed by high-
RT density pyrosequencing and transposon mutagenesis.";
RL Genes Dev. 21:601-614(2007).
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; CP000521; ABO13317.2; -; Genomic_DNA.
DR RefSeq; WP_000667229.1; NZ_CP053098.1.
DR AlphaFoldDB; A3M8S3; -.
DR SMR; A3M8S3; -.
DR KEGG; acb:A1S_2912; -.
DR HOGENOM; CLU_022060_0_1_6; -.
DR UniPathway; UPA00392; -.
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..377
FT /note="Queuine tRNA-ribosyltransferase"
FT /id="PRO_1000097524"
FT REGION 246..252
FT /note="RNA binding"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00168"
FT REGION 270..274
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 265
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 188
FT /ligand="substrate"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00168"
FT BINDING 215
FT /ligand="substrate"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00168"
FT BINDING 303
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00168"
FT BINDING 305
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00168"
FT BINDING 308
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00168"
FT BINDING 334
FT /ligand="Zn(2+)"
FT /ligand_id="ChEBI:CHEBI:29105"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_00168"
SQ SEQUENCE 377 AA; 42912 MW; B85A85E8C2D96B38 CRC64;
MKFEKLGQSG RARRGRLTLE HGVVETPVFM PVGTYGTVKG MLPRDIEDIQ AQIILGNTFH
LYLRPGLEVI KQHGGLHDFI KWNKPILTDS GGFQVFSLGA MRKIKEEGVT FRSPIDGSKV
FLSPEISMEI QHVLNSDIVM IFDECTPYPA THEEAQKSLQ LSLRWAKRCK AHHHDELKNK
NALFGIIQGG MYEDLRDESL NGLLEIGFDG YAIGGLSVGE PKEEMIKVLD YLPNKMPHDK
PRYLMGVGKP EDIVEAVRRG VDMFDCVMPT RNARNGHYFV TDGLVRIRNS KYRHDQGPLD
PHCDCYTCKN FTRAYLFHLE KCGEMLASML GTIHNLRYYQ RLTEGMRDAL DNGTFDEFVQ
DFYARRGLEV PPCPVDE
