TRNA(His) guanylyltransferase

Template:Infobox enzyme tRNA(His) guanylyltransferase (Template:EC number, histidine tRNA guanylyltransferase, Thg1p, Thg1) is an enzyme with systematic name p-tRNA(His):GTP guanylyltransferase (ATP-hydrolysing).^[1]^[2]^[3]^[4]^[5]^[6] This enzyme catalyses the following chemical reaction

p-tRNA(His) + ATP + GTP

⇌

pppGp-tRNA(His) + AMP + diphosphate (overall reaction)

(1a) p-tRNA(His) + ATP

⇌

App-tRNA(His) + diphosphate

(1b) App-tRNA(His) + GTP

⇌

pppGp-tRNA(His) + AMP

The enzyme requires a divalent cation for activity.

References