Protein Family Models

This is a family of queuine tRNA-ribosyltransferases EC:2.4.2.29, also known as tRNA-guanine transglycosylase and guanine insertion enzyme. Queuine tRNA-ribosyltransferase modifies tRNAs for asparagine, aspartic acid, histidine and tyrosine with queuine. It catalyses the exchange of guanine-34 at the wobble position with 7-aminomethyl-7-deazaguanine, and the addition of a cyclopentenediol moiety to 7-aminomethyl-7-deazaguanine-34 tRNA; giving a hypermodified base queuine in the wobble position [1,2]. The aligned region contains a zinc binding motif C-x-C-x2-C-x29-H, and important tRNA and 7-aminomethyl-7deazaguanine binding residues [1]. [1]. 8654383. Crystal structure of tRNA-guanine transglycosylase: RNA modification by base exchange. Romier C, Reuter K, Suck D, Ficner R;. EMBO J 1996;15:2850-2857. [2]. 8323579. tRNA-guanine transglycosylase from Escherichia coli. Overexpression, purification and quaternary structure. Garcia GA, Koch KA, Chong S;. J Mol Biol 1993;231:489-497. (from Pfam)

Date:

2024-10-16

tRNA guanosine(34) transglycosylase Tgt catalyzes the base-exchange of a guanine (G) residue with queuine (Q) at position 34 in tRNAs with GU(N) anticodons resulting in the hypermodified nucleoside queuosine

Date:

2024-08-01

This tRNA-guanine transglycosylase includes enzymes that replace guanine at position 34 in bacteria with queuine (Tgt), and at position 15 in archaea with 7-cyano-7-carbaguanine.

Date:

2022-03-28

This tRNA-guanine transglycosylase (tgt) catalyzes an exchange for the guanine base at position 34 of many tRNAs; this nucleotide is subsequently modified to queuosine. The Archaea have a closely related enzyme that catalyzes a base exchange for guanine at position 15 in some tRNAs, a site that is subsequently converted to the archaeal-specific modified base archaeosine (7-formamidino-7-deazaguanosine), while Archaeoglobus fulgidus has both enzymes.

Gene:

tgt

Date:

2021-04-27