DB code: S00230

RLCP classification 3.944.220700.2 : Transfer
CATH domain 3.20.20.105 : TIM Barrel Catalytic domain
E.C. 2.4.2.29
CSA 1pud
M-CSA 1pud
MACiE

CATH domain Related DB codes (homologues)

Uniprot Enzyme Name
UniprotKB Protein name Synonyms RefSeq Pfam
P28720 Queuine tRNA-ribosyltransferase
EC 2.4.2.29
tRNA-guanine transglycosylase
Guanine insertion enzyme
YP_162098.2 (Protein)
NC_006526.2 (DNA/RNA sequence)
PF01702 (TGT)
[Graphical View]
Q9X1P7 Queuine tRNA-ribosyltransferase
EC 2.4.2.29
tRNA-guanine transglycosylase
Guanine insertion enzyme
NP_229361.1 (Protein)
NC_000853.1 (DNA/RNA sequence)
PF01702 (TGT)
[Graphical View]

KEGG enzyme name
tRNA-guanine transglycosylase
guanine insertion enzyme
tRNA transglycosylase
Q-insertase
queuine transfer ribonucleate ribosyltransferase
transfer ribonucleate glycosyltransferase
tRNA guanine transglycosidase
guanine, queuine-tRNA transglycosylase
queuine tRNA-ribosyltransferase
TGT
[tRNA]-guanine:queuine tRNA-D-ribosyltransferase
transfer ribonucleic acid guanine transglycosylase

UniprotKB: Accession Number Entry name Activity Subunit Subcellular location Cofactor
P28720 TGT_ZYMMO [tRNA]-guanine + queuine = [tRNA]-queuine + guanine. [tRNA]-guanine + 7-aminomethyl-7-carbaguanine = [tRNA]-7-aminomethyl-7-carbaguanine + guanine. Monomer. Binds 1 zinc ion per subunit.
Q9X1P7 TGT_THEMA [tRNA]-guanine + queuine = [tRNA]-queuine + guanine. [tRNA]-guanine + 7-aminomethyl-7-carbaguanine = [tRNA]-7-aminomethyl-7-carbaguanine + guanine. Binds 1 zinc ion per subunit (By similarity).

KEGG Pathways
Map code Pathways E.C.

Compound table
Cofactors Substrates Products Intermediates
KEGG-id C00038 C01977 C01449 C01978 C00242
E.C.
Compound Zinc tRNA guanine Queuine tRNA queuine Guanine enzyme-tRNA covalent intermediate
Type heavy metal amide group,amine group,nucleic acids amide group,amine group,aromatic ring (with nitrogen atoms),carbohydrate amide group,amine group,carbohydrate,nucleic acids amide group,amine group,aromatic ring (with nitrogen atoms)
ChEBI 29105
29105
17433
17433
16235
16235
PubChem 32051
32051
114881
114881
764
764
1efzA Bound:_ZN Unbound Analogue:PRF Unbound Unbound Unbound
1enuA Bound:_ZN Unbound Unbound Unbound Analogue:APZ Unbound
1f3eA Bound:_ZN Unbound Unbound Unbound Analogue:DPZ Unbound
1k4gA Bound:_ZN Unbound Analogue:AIQ Unbound Unbound Unbound
1k4hA Bound:_ZN Unbound Analogue:APQ Unbound Unbound Unbound
1n2vA Bound:_ZN Unbound Analogue:BDI Unbound Unbound Unbound
1ozmA Bound:_ZN Unbound Unbound Unbound Unbound Unbound
1ozqA Bound:_ZN Unbound Analogue:PRF Unbound Unbound Unbound
1p0bA Bound:_ZN Unbound Analogue:PQ0 Unbound Unbound Unbound
1p0dA Bound:_ZN Unbound Unbound Unbound Unbound Unbound
1p0eA Bound:_ZN Unbound Analogue:PRF Unbound Unbound Unbound
1pudA Bound:_ZN Unbound Unbound Unbound Unbound Unbound
1pxgA Bound:_ZN Unbound Analogue:PRF Unbound Unbound Unbound
1q2rA Bound:_ZN Unbound Unbound Unbound Analogue:9DG Bound:ASP_280-ROB (chain E)
1q2rB Bound:_ZN Unbound Unbound Unbound Analogue:9DG Unbound
1q2rC Bound:_ZN Unbound Unbound Unbound Analogue:9DG Bound:ASP_280-ROB (chain F)
1q2rD Bound:_ZN Unbound Unbound Unbound Analogue:9DG Unbound
1q2sA Bound:_ZN Unbound Unbound Analogue:A-G-C-A-C-G-G-C-U-PQ1-U-A-A-A-C-C-G-U-G-C (chain E) Unbound Unbound
1q2sB Bound:_ZN Unbound Unbound Unbound Unbound Unbound
1q2sC Bound:_ZN Unbound Unbound Unbound Analogue:9DG Analogue:ASP_280-ROB (chain F)
1q2sD Bound:_ZN Unbound Unbound Unbound Unbound Unbound
1q4wA Bound:_ZN Unbound Unbound Unbound Analogue:DQU Unbound
1q63A Bound:_ZN Unbound Analogue:AIQ Unbound Unbound Unbound
1q65A Bound:_ZN Unbound Analogue:BHB Unbound Unbound Unbound
1q66A Bound:_ZN Unbound Analogue:KMB Unbound Unbound Unbound
1r5yA Bound:_ZN Unbound Unbound Unbound Analogue:DQU Unbound
1s38A Bound:_ZN Unbound Unbound Unbound Analogue:MAQ Unbound
1s39A Bound:_ZN Unbound Unbound Unbound Analogue:AQO Unbound
1wkdA Bound:_ZN Unbound Unbound Unbound Unbound Unbound
1wkeA Bound:_ZN Unbound Unbound Unbound Unbound Unbound
1wkfA Bound:_ZN Unbound Unbound Unbound Unbound Unbound
1y5vA Bound:_ZN Unbound Analogue:NE8 Unbound Unbound Unbound
1y5wA Bound:_ZN Unbound Analogue:NEZ Unbound Unbound Unbound
1y5xA Bound:_ZN Unbound Analogue:E89 Unbound Unbound Unbound
1y5xD Bound:_ZN Unbound Analogue:E89 Unbound Unbound Unbound
2ashA Bound:_ZN Unbound Unbound Unbound Unbound Unbound
2ashB Bound:_ZN Unbound Unbound Unbound Unbound Unbound
2ashC Bound:_ZN Unbound Unbound Unbound Unbound Unbound
2ashD Bound:_ZN Unbound Unbound Unbound Unbound Unbound

Reference for Active-site residues
resource references E.C.
Swiss-prot;P28720 & literature [29], [31]

Active-site residues
PDB Catalytic residues Cofactor-binding residues Modified residues Main-chain involved in catalysis Comment
1efzA ASP 102;ASP 280 CYS 318;CYS 320;CYS 323;HIS 349(Zinc binding) mutant S103A
1enuA ASP 102;ASP 280 CYS 318;CYS 320;CYS 323;HIS 349(Zinc binding)
1f3eA ASP 102;ASP 280 CYS 318;CYS 320;CYS 323;HIS 349(Zinc binding)
1k4gA ASP 102;ASP 280 CYS 318;CYS 320;CYS 323;HIS 349(Zinc binding)
1k4hA ASP 102;ASP 280 CYS 318;CYS 320;CYS 323;HIS 349(Zinc binding)
1n2vA ASP 102;ASP 280 CYS 318;CYS 320;CYS 323;HIS 349(Zinc binding)
1ozmA ASP 102;ASP 280 CYS 318;CYS 320;CYS 323;HIS 349(Zinc binding) mutant Y106F
1ozqA ASP 102;ASP 280 CYS 318;CYS 320;CYS 323;HIS 349(Zinc binding) mutant Y106F
1p0bA ASP 102;ASP 280 CYS 318;CYS 320;CYS 323;HIS 349(Zinc binding)
1p0dA ASP 102;ASP 280 CYS 318;CYS 320;CYS 323;HIS 349(Zinc binding)
1p0eA ASP 102;ASP 280 CYS 318;CYS 320;CYS 323;HIS 349(Zinc binding)
1pudA ASP 102;ASP 280 CYS 318;CYS 320;CYS 323;HIS 349(Zinc binding)
1pxgA ASP 102; CYS 318;CYS 320;CYS 323;HIS 349(Zinc binding) mutant D280E
1q2rA ASP 102;ASP 280 CYS 318;CYS 320;CYS 323;HIS 349(Zinc binding)
1q2rB ASP 102;ASP 280 CYS 318;CYS 320;CYS 323;HIS 349(Zinc binding)
1q2rC ASP 102;ASP 280 CYS 318;CYS 320;CYS 323;HIS 349(Zinc binding)
1q2rD ASP 102;ASP 280 CYS 318;CYS 320;CYS 323;HIS 349(Zinc binding)
1q2sA ASP 102;ASP 280 CYS 318;CYS 320;CYS 323;HIS 349(Zinc binding)
1q2sB ASP 102;ASP 280 CYS 318;CYS 320;CYS 323;HIS 349(Zinc binding)
1q2sC ASP 102;ASP 280 CYS 318;CYS 320;CYS 323;HIS 349(Zinc binding)
1q2sD ASP 102;ASP 280 CYS 318;CYS 320;CYS 323;HIS 349(Zinc binding)
1q4wA ASP 102;ASP 280 CYS 318;CYS 320;CYS 323;HIS 349(Zinc binding)
1q63A ASP 102;ASP 280 CYS 318;CYS 320;CYS 323;HIS 349(Zinc binding)
1q65A ASP 102;ASP 280 CYS 318;CYS 320;CYS 323;HIS 349(Zinc binding)
1q66A ASP 102;ASP 280 CYS 318;CYS 320;CYS 323;HIS 349(Zinc binding)
1r5yA ASP 102;ASP 280 CYS 318;CYS 320;CYS 323;HIS 349(Zinc binding)
1s38A ASP 102;ASP 280 CYS 318;CYS 320;CYS 323;HIS 349(Zinc binding)
1s39A ASP 102;ASP 280 CYS 318;CYS 320;CYS 323;HIS 349(Zinc binding)
1wkdA ;ASP 280 CYS 318;CYS 320;CYS 323;HIS 349(Zinc binding) mutant D102A
1wkeA ASP 102;ASP 280 CYS 318;CYS 320;CYS 323;HIS 349(Zinc binding) mutant D156A
1wkfA ASP 102;ASP 280 CYS 318;CYS 320;CYS 323;HIS 349(Zinc binding) mutant D156Y
1y5vA ASP 102;ASP 280 CYS 318;CYS 320;CYS 323;HIS 349(Zinc binding)
1y5wA ASP 102;ASP 280 CYS 318;CYS 320;CYS 323;HIS 349(Zinc binding)
1y5xA ASP 102;ASP 280 CYS 318;CYS 320;CYS 323;HIS 349(Zinc binding)
1y5xD ASP 1102;ASP 1280 CYS 1318;CYS 1320;CYS 1323;HIS 1349(Zinc binding)
2ashA ASP 89;ASP 261 CYS 299;CYS 301;CYS 304;HIS 330(Zinc binding)
2ashB ASP 89;ASP 261 CYS 299;CYS 301;CYS 304;HIS 330(Zinc binding)
2ashC ASP 89;ASP 261 CYS 299;CYS 301;CYS 304;HIS 330(Zinc binding)
2ashD ASP 89;ASP 261 CYS 299;CYS 301;CYS 304;HIS 330(Zinc binding)

References for Catalytic Mechanism
References Sections No. of steps in catalysis
[15]
Fig.4, p.15738
[16]
p.2853-2855
[21]
Fig.4, p.145
[22]
Fig.2, p.14128-14132
[27]
Fig.1, p.1072-1074
[29]
Fig.2, Fig.4, Fig.7, p.42376
[31]
Fig.1, p.772
[32]
p.786-787
[33]
Fig.2, p.56

References
[1]
Resource
Comments
Medline ID
PubMed ID 6696916
Journal Biochim Biophys Acta
Year 1984
Volume 781
Pages 64-75
Authors Farkas WR, Jacobson KB, Katze JR
Title Substrate and inhibitor specificity of tRNA-guanine ribosyltransferase
Related PDB
Related UniProtKB
[2]
Resource
Comments
Medline ID
PubMed ID 3117541
Journal Eur J Biochem
Year 1987
Volume 168
Pages 219-25
Authors Haumont E, Droogmans L, Grosjean H
Title Enzymatic formation of queuosine and of glycosyl queuosine in yeast tRNAs microinjected into Xenopus laevis oocytes. The effect of the anticodon loop sequence
Related PDB
Related UniProtKB
[3]
Resource
Comments
Medline ID
PubMed ID 8494901
Journal Biochemistry
Year 1993
Volume 32
Pages 5239-46
Authors Curnow AW, Kung FL, Koch KA, Garcia GA
Title tRNA-guanine transglycosylase from Escherichia coli
Related PDB
Related UniProtKB
[4]
Resource
Comments
Medline ID
PubMed ID 8323579
Journal J Mol Biol
Year 1993
Volume 231
Pages 489-97
Authors Garcia GA, Koch KA, Chong S
Title tRNA-guanine transglycosylase from Escherichia coli. Overexpression, purification and quaternary structure
Related PDB
Related UniProtKB
[5]
Resource
Comments
Medline ID
PubMed ID 8003468
Journal Biochemistry
Year 1994
Volume 33
Pages 7041-6
Authors Reuter K, Chong S, Ullrich F, Kersten H, Garcia GA
Title Serine 90 is required for enzymic activity by tRNA-guanine transglycosylase from Escherichia coli
Related PDB
Related UniProtKB
[6]
Resource
Comments
Medline ID
PubMed ID 7748954
Journal Biochimie
Year 1994
Volume 76
Pages 1183-91
Authors Curnow AW, Garcia GA
Title tRNA-guanine transglycosylase from Escherichia coli
Related PDB
Related UniProtKB
[7]
Resource
Comments
Medline ID
PubMed ID 7528209
Journal J Biol Chem
Year 1994
Volume 269
Pages 32221-5
Authors Nakanishi S, Ueda T, Hori H, Yamazaki N, Okada N, Watanabe K
Title A UGU sequence in the anticodon loop is a minimum requirement for recognition by Escherichia coli tRNA-guanine transglycosylase
Related PDB
Related UniProtKB
[8]
Resource
Comments
Medline ID
PubMed ID 7893665
Journal Biochemistry
Year 1995
Volume 34
Pages 3694-701
Authors Chong S, Curnow AW, Huston TJ, Garcia GA
Title tRNA-guanine transglycosylase from Escherichia coli is a zinc metalloprotein. Site-directed mutagenesis studies to identify the zinc ligands
Related PDB
Related UniProtKB
[9]
Resource
Comments
Medline ID
PubMed ID 7492556
Journal Biochemistry
Year 1995
Volume 34
Pages 15539-44
Authors Hoops GC, Townsend LB, Garcia GA
Title Mechanism-based inactivation of tRNA-guanine transglycosylase from Escherichia coli by 2-amino-5-(fluoromethyl)pyrrolo[2,3-d]pyrimidin-4 (3H)-one
Related PDB
Related UniProtKB
[10]
Resource
Comments
Medline ID
PubMed ID 7578154
Journal Biochemistry
Year 1995
Volume 34
Pages 15381-7
Authors Hoops GC, Townsend LB, Garcia GA
Title tRNA-guanine transglycosylase from Escherichia coli
Related PDB
Related UniProtKB
[11]
Resource
Comments
Medline ID
PubMed ID 7665516
Journal J Bacteriol
Year 1995
Volume 177
Pages 5284-8
Authors Reuter K, Ficner R
Title Sequence analysis and overexpression of the Zymomonas mobilis tgt gene encoding tRNA-guanine transglycosylase
Related PDB
Related UniProtKB
[12]
Resource
Comments
Medline ID
PubMed ID 7615526
Journal J Biol Chem
Year 1995
Volume 270
Pages 17264-7
Authors Curnow AW, Garcia GA
Title tRNA-guanine transglycosylase from Escherichia coli. Minimal tRNA structure and sequence requirements for recognition.
Related PDB
Related UniProtKB
[13]
Resource
Comments
Medline ID
PubMed ID 8579355
Journal Arch Biochem Biophys
Year 1996
Volume 326
Pages 1-7
Authors Deshpande KL, Seubert PH, Tillman DM, Farkas WR, Katze JR
Title Cloning and characterization of cDNA encoding the rabbit tRNA-guanine transglycosylase 60-kilodalton subunit
Related PDB
Related UniProtKB
[14]
Resource
Comments
Medline ID
PubMed ID 8608154
Journal Biochemistry
Year 1996
Volume 35
Pages 3133-9
Authors Garcia GA, Tierney DL, Chong S, Clark K, Penner-Hahn JE
Title X-ray absorption spectroscopy of the zinc site in tRNA-guanine transglycosylase from Escherichia coli
Related PDB
Related UniProtKB
[15]
Resource
Comments X-ray crystallography
Medline ID
PubMed ID 8961936
Journal Biochemistry
Year 1996
Volume 35
Pages 15734-9
Authors Romier C, Reuter K, Suck D, Ficner R
Title Mutagenesis and crystallographic studies of Zymomonas mobilis tRNA-guanine transglycosylase reveal aspartate 102 as the active site nucleophile
Related PDB 1wkd 1wke 1wkf
Related UniProtKB
[16]
Resource
Comments X-RAY CRYSTALLOGRAPHY (1.85 ANGSTROMS).
Medline ID 96256303
PubMed ID 8654383
Journal EMBO J
Year 1996
Volume 15
Pages 2850-7
Authors Romier C, Reuter K, Suck D, Ficner R
Title Crystal structure of tRNA-guanine transglycosylase
Related PDB 1pud
Related UniProtKB P28720
[17]
Resource
Comments
Medline ID
PubMed ID 8860000
Journal Proteins
Year 1996
Volume 24
Pages 516-9
Authors Romier C, Ficner R, Reuter K, Suck D
Title Purification, crystallization, and preliminary x-ray diffraction studies of tRNA-guanine transglycosylase from Zymomonas mobilis
Related PDB
Related UniProtKB
[18]
Resource
Comments
Medline ID
PubMed ID 9369241
Journal FEBS Lett
Year 1997
Volume 416
Pages 93-8
Authors Romier C, Meyer JE, Suck D
Title Slight sequence variations of a common fold explain the substrate specificities of tRNA-guanine transglycosylases from the three kingdoms
Related PDB
Related UniProtKB
[19]
Resource
Comments
Medline ID
PubMed ID 9055203
Journal J Protein Chem
Year 1997
Volume 16
Pages 11-7
Authors Garcia GA, Chong S
Title Cysteine 265 is in the active site of, but is not essential for catalysis by tRNA-guanine transglycosylase (TGT) from Escherichia coli
Related PDB
Related UniProtKB
[20]
Resource
Comments
Medline ID
PubMed ID 9403840
Journal Med Microbiol Immunol (Berl)
Year 1997
Volume 186
Pages 125-34
Authors Bereswill S, Fassbinder F, Volzing C, Haas R, Reuter K, Ficner R, Kist M
Title Cloning and functional characterization of the genes encoding 3-dehydroquinate synthase (aroB) and tRNA-guanine transglycosylase (tgt) from Helicobacter pylori
Related PDB
Related UniProtKB
[21]
Resource
Comments X-RAY CRYSTALLOGRAPHY (2.0 ANGSTROMS) OF 10-381, AND MUTAGENESIS OF SER-102.
Medline ID
PubMed ID 10413112
Journal FEBS Lett
Year 1999
Volume 454
Pages 142-6
Authors Gradler U, Ficner R, Garcia GA, Stubbs MT, Klebe G, Reuter K
Title Mutagenesis and crystallographic studies of Zymomonas mobilis tRNA-guanine transglycosylase to elucidate the role of serine 103 for enzymatic activity
Related PDB 1efz
Related UniProtKB P28720
[22]
Resource
Comments
Medline ID
PubMed ID 11714265
Journal Biochemistry
Year 2001
Volume 40
Pages 14123-33
Authors Kittendorf JD, Barcomb LM, Nonekowski ST, Garcia GA
Title tRNA-guanine transglycosylase from Escherichia coli
Related PDB
Related UniProtKB
[23]
Resource
Comments
Medline ID
PubMed ID 11255023
Journal Gene
Year 2001
Volume 265
Pages 205-12
Authors Deshpande KL, Katze JR
Title Characterization of cDNA encoding the human tRNA-guanine transglycosylase (TGT) catalytic subunit
Related PDB
Related UniProtKB
[24]
Resource
Comments X-RAY CRYSTALLOGRAPHY (1.95 ANGSTROMS).
Medline ID 21103718
PubMed ID 11178905
Journal J Mol Biol
Year 2001
Volume 306
Pages 455-67
Authors Gradler U, Gerber HD, Goodenough-Lashua DM, Garcia GA, Ficner R, Reuter K, Stubbs MT, Klebe G
Title A new target for shigellosis
Related PDB 1f3e
Related UniProtKB P28720
[25]
Resource
Comments X-RAY CRYSTALLOGRAPHY (1.8 ANGSTROMS) OF 11-385.
Medline ID
PubMed ID 11921407
Journal Chembiochem
Year 2002
Volume 3
Pages 250-3
Authors Meyer EA, Brenk R, Castellano RK, Furler M, Klebe G, Diederich F
Title De novo design, synthesis, and in vitro evaluation of inhibitors for prokaryotic tRNA-guanine transglycosylase
Related PDB 1k4g 1k4h
Related UniProtKB P28720
[26]
Resource
Comments
Medline ID
PubMed ID 11751936
Journal J Biol Chem
Year 2002
Volume 277
Pages 7178-82
Authors Nonekowski ST, Kung FL, Garcia GA
Title The Escherichia coli tRNA-guanine transglycosylase can recognize and modify DNA
Related PDB
Related UniProtKB
[27]
Resource
Comments X-ray crystallography
Medline ID
PubMed ID 14523925
Journal Chembiochem
Year 2003
Volume 4
Pages 1066-77
Authors Brenk R, Stubbs MT, Heine A, Reuter K, Klebe G
Title Flexible adaptations in the structure of the tRNA-modifying enzyme tRNA-guanine transglycosylase and their implications for substrate selectivity, reaction mechanism and structure-based drug design.
Related PDB 1ozm 1ozq 1p0b 1p0d 1p0e
Related UniProtKB
[28]
Resource
Comments
Medline ID
PubMed ID 12581659
Journal Curr Opin Struct Biol
Year 2003
Volume 13
Pages 49-55
Authors Ferre-D'Amare AR
Title RNA-modifying enzymes.
Related PDB
Related UniProtKB
[29]
Resource
Comments
Medline ID
PubMed ID 12909636
Journal J Biol Chem
Year 2003
Volume 278
Pages 42369-76
Authors Kittendorf JD, Sgraja T, Reuter K, Klebe G, Garcia GA
Title An essential role for aspartate 264 in catalysis by tRNA-guanine transglycosylase from Escherichia coli.
Related PDB 1pxg
Related UniProtKB
[30]
Resource
Comments X-RAY CRYSTALLOGRAPHY (2.1 ANGSTROMS) OF 11-385.
Medline ID
PubMed ID 12646024
Journal J Med Chem
Year 2003
Volume 46
Pages 1133-43
Authors Brenk R, Naerum L, Gradler U, Gerber HD, Garcia GA, Reuter K, Stubbs MT, Klebe G
Title Virtual screening for submicromolar leads of tRNA-guanine transglycosylase based on a new unexpected binding mode detected by crystal structure analysis.
Related PDB 1n2v
Related UniProtKB P28720
[31]
Resource
Comments
Medline ID
PubMed ID 14513020
Journal Nat Struct Biol
Year 2003
Volume 10
Pages 772-3
Authors Correll CC
Title Caught in the act of modifying tRNA.
Related PDB
Related UniProtKB
[32]
Resource
Comments
Medline ID
PubMed ID 12949492
Journal Nat Struct Biol
Year 2003
Volume 10
Pages 781-8
Authors Xie W, Liu X, Huang RH
Title Chemical trapping and crystal structure of a catalytic tRNA guanine transglycosylase covalent intermediate.
Related PDB 1q2r 1q2s
Related UniProtKB
[33]
Resource
Comments
Medline ID
PubMed ID 15050823
Journal J Mol Biol
Year 2004
Volume 338
Pages 55-75
Authors Brenk R, Meyer EA, Reuter K, Stubbs MT, Garcia GA, Diederich F, Klebe G
Title Crystallographic study of inhibitors of tRNA-guanine transglycosylase suggests a new structure-based pharmacophore for virtual screening.
Related PDB 1q4w 1q63 1q65 1q66 1r5y
Related UniProtKB
[34]
Resource
Comments
Medline ID
PubMed ID
Journal Helv Chim Acta
Year 2004
Volume 87
Pages 1333-56g
Authors Meyer EA, Furler M, Diederich F, Brenk R, Klebe G
Title Synthesis and in vitro evaluation of 2-aminoquinazolin-4(3h)-one-based inhibitors for tRNA-guanine transglycosylase (tgt).
Related PDB 1s38 1s39
Related UniProtKB

Comments
Although this enzyme binds a zinc ion, it is not involved in catalysis.
According to the literature [31] and [32], the catalytic reaction proceeds as follows:
(1) Asp280 makes a nucleophilic attack on the C1' atom of tRNA ribose, while Asp102 acts as a general acid to protonate the leaving group, N9 atom of guanine. This reaction proceeds via SN2-like mechanism, forming an enzyme-tRNA covalent intermediate.
(2) Asp102 acts as a general base activate the N9 atom of queine(or preQ1), the acceptor group, by deprotonating it.
(3) The activated queine (or preQ1) makes a nucleophilic attack on the C1' atom of the intermediate, completing the reaction.

Created Updated
2005-03-29 2009-02-26