From Wikipedia, the free encyclopedia
tRNA(His) guanylyltransferase (
EC
2.7.7.79 , 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
⇌
{\displaystyle \rightleftharpoons }
pppGp-tRNA(His) + AMP +
diphosphate (overall reaction)
(1a) p-tRNA(His) + ATP
⇌
{\displaystyle \rightleftharpoons }
App-tRNA(His) + diphosphate
(1b) App-tRNA(His) + GTP
⇌
{\displaystyle \rightleftharpoons }
pppGp-tRNA(His) + AMP
The enzyme requires a divalent cation for activity.
References
^ Jahn D, Pande S (December 1991).
"Histidine tRNA guanylyltransferase from Saccharomyces cerevisiae. II. Catalytic mechanism" . The Journal of Biological Chemistry . 266 (34): 22832–6.
doi :
10.1016/S0021-9258(18)54429-X .
PMID
1660462 .
^ Pande S, Jahn D, Söll D (December 1991).
"Histidine tRNA guanylyltransferase from Saccharomyces cerevisiae. I. Purification and physical properties" . The Journal of Biological Chemistry . 266 (34): 22826–31.
doi :
10.1016/S0021-9258(18)54428-8 .
PMID
1660461 .
^ Gu W, Jackman JE, Lohan AJ, Gray MW, Phizicky EM (December 2003).
"tRNAHis maturation: an essential yeast protein catalyzes addition of a guanine nucleotide to the 5' end of tRNAHis" . Genes & Development . 17 (23): 2889–901.
doi :
10.1101/gad.1148603 .
PMC
289149 .
PMID
14633974 .
^ Placido A, Sieber F, Gobert A, Gallerani R, Giegé P, Maréchal-Drouard L (November 2010).
"Plant mitochondria use two pathways for the biogenesis of tRNAHis" . Nucleic Acids Research . 38 (21): 7711–7.
doi :
10.1093/nar/gkq646 .
PMC
2995067 .
PMID
20660484 .
^ Jackman JE, Phizicky EM (April 2008). "Identification of critical residues for G-1 addition and substrate recognition by tRNA(His) guanylyltransferase". Biochemistry . 47 (16): 4817–25.
doi :
10.1021/bi702517q .
PMID
18366186 .
^ Hyde SJ, Eckenroth BE, Smith BA, Eberley WA, Heintz NH, Jackman JE, Doublié S (November 2010).
"tRNA(His) guanylyltransferase (THG1), a unique 3'-5' nucleotidyl transferase, shares unexpected structural homology with canonical 5'-3' DNA polymerases" . Proceedings of the National Academy of Sciences of the United States of America . 107 (47): 20305–10.
doi :
10.1073/pnas.1010436107 .
PMC
2996709 .
PMID
21059936 .
External links
Activity Regulation Classification Kinetics Types