Biology:TRNA(His) guanylyltransferase

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tRNA(His) guanylyltransferase
Identifiers
EC number2.7.7.79
Databases
IntEnzIntEnz view
BRENDABRENDA entry
ExPASyNiceZyme view
KEGGKEGG entry
MetaCycmetabolic pathway
PRIAMprofile
PDB structuresRCSB PDB PDBe PDBsum

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 [math]\displaystyle{ \rightleftharpoons }[/math] pppGp-tRNA(His) + AMP + diphosphate (overall reaction)
(1a) p-tRNA(His) + ATP [math]\displaystyle{ \rightleftharpoons }[/math] App-tRNA(His) + diphosphate
(1b) App-tRNA(His) + GTP [math]\displaystyle{ \rightleftharpoons }[/math] pppGp-tRNA(His) + AMP

The enzyme requires a divalent cation for activity.

References

  1. "Histidine tRNA guanylyltransferase from Saccharomyces cerevisiae. II. Catalytic mechanism". The Journal of Biological Chemistry 266 (34): 22832–6. December 1991. doi:10.1016/S0021-9258(18)54429-X. PMID 1660462. 
  2. "Histidine tRNA guanylyltransferase from Saccharomyces cerevisiae. I. Purification and physical properties". The Journal of Biological Chemistry 266 (34): 22826–31. December 1991. doi:10.1016/S0021-9258(18)54428-8. PMID 1660461. 
  3. "tRNAHis maturation: an essential yeast protein catalyzes addition of a guanine nucleotide to the 5' end of tRNAHis". Genes & Development 17 (23): 2889–901. December 2003. doi:10.1101/gad.1148603. PMID 14633974. 
  4. "Plant mitochondria use two pathways for the biogenesis of tRNAHis". Nucleic Acids Research 38 (21): 7711–7. November 2010. doi:10.1093/nar/gkq646. PMID 20660484. 
  5. "Identification of critical residues for G-1 addition and substrate recognition by tRNA(His) guanylyltransferase". Biochemistry 47 (16): 4817–25. April 2008. doi:10.1021/bi702517q. PMID 18366186. 
  6. "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. November 2010. doi:10.1073/pnas.1010436107. PMID 21059936. 

External links