TRNAHis guanylyltransferase

TRNAHis guanylyltransferase (EC 2.7.7.79, histidine tRNA guanylyltransferase, Thg1p, Thg1) is an enzyme with systematic name p-tRNAHis:GTP guanylyltransferase (ATP-hydrolysing).^[1]^[2]^[3]^[4]^[5]^[6] This enzyme catalyses the following chemical reaction

p-tRNAHis + ATP + GTP

\rightleftharpoons

pppGp-tRNAHis + AMP + diphosphate (overall reaction)

(1a) p-tRNAHis + ATP

\rightleftharpoons

App-tRNAHis + diphosphate

(1b) App-tRNAHis + GTP

\rightleftharpoons

pppGp-tRNAHis + AMP

The enzyme requires a divalent cation for activity.

References

↑ Jahn, D. and Pande, S. (1991). "Histidine tRNA guanylyltransferase from Saccharomyces cerevisiae. II. Catalytic mechanism". J. Biol. Chem. 266 (34): 22832–22836. PMID 1660462.
↑ Pande, S., Jahn, D. and Soll, D. (1991). "Histidine tRNA guanylyltransferase from Saccharomyces cerevisiae. I. Purification and physical properties". J. Biol. Chem. 266 (34): 22826–22831. PMID 1660461.
↑ Gu, W., Jackman, J.E., Lohan, A.J., Gray, M.W. and Phizicky, E.M. (2003). "tRNA^His maturation: an essential yeast protein catalyzes addition of a guanine nucleotide to the 5′ end of tRNA^His". Genes Dev. 17 (23): 2889–2901. doi:10.1101/gad.1148603. PMID 14633974.
↑ Placido, A., Sieber, F., Gobert, A., Gallerani, R., Giege, P. and Marechal-Drouard, L. (2010). "Plant mitochondria use two pathways for the biogenesis of tRNA^His". Nucleic Acids Res. 38 (21): 7711–7717. doi:10.1093/nar/gkq646. PMID 20660484.
↑ Jackman, J.E. and Phizicky, E.M. (2008). "Identification of critical residues for G-1 addition and substrate recognition by tRNA(His) guanylyltransferase". Biochemistry 47 (16): 4817–4825. doi:10.1021/bi702517q. PMID 18366186.
↑ Hyde, S.J., Eckenroth, B.E., Smith, B.A., Eberley, W.A., Heintz, N.H., Jackman, J.E. and Doublie, S. (2010). "tRNA(His) guanylyltransferase (THG1), a unique 3′-5′ nucleotidyl transferase, shares unexpected structural homology with canonical 5′-3′ DNA polymerases". Proc. Natl. Acad. Sci. USA 107 (47): 20305–20310. doi:10.1073/pnas.1010436107. PMID 21059936.

External links

TRNAHis guanylyltransferase at the US National Library of Medicine Medical Subject Headings (MeSH)

Transferases: phosphorus-containing groups (EC 2.7)

2.7.1-2.7.4:
phosphotransferase/kinase
(PO₄)

2.7.1: OH acceptor	Hexo- Gluco- Fructo- Hepatic Galacto- Phosphofructo- 1 Liver Muscle Platelet 2 Riboflavin Shikimate Thymidine ADP-thymidine NAD⁺ Glycerol Pantothenate Mevalonate Pyruvate Deoxycytidine PFP Diacylglycerol Phosphoinositide 3 Class I PI 3 Class II PI 3 Sphingosine Glucose-1,6-bisphosphate synthase

2.7.2: COOH acceptor	Phosphoglycerate Aspartate kinase

2.7.3: N acceptor	Creatine

2.7.4: PO₄ acceptor	Phosphomevalonate Adenylate Nucleoside-diphosphate Uridylate Guanylate Thiamine-diphosphate

2.7.6: diphosphotransferase
(P₂O₇)

2.7.7: nucleotidyltransferase
(PO₄-nucleoside)

Polymerase

DNA polymerase	DNA-directed DNA polymerase I II III IV V RNA-directed DNA polymerase Reverse transcriptase Telomerase DNA nucleotidylexotransferase/Terminal deoxynucleotidyl transferase

RNA nucleotidyltransferase	RNA polymerase/DNA-directed RNA polymerase RNA polymerase I RNA polymerase II RNA polymerase III RNA polymerase IV Primase RNA-dependent RNA polymerase PNPase

Phosphorolytic
3' to 5' exoribonuclease

Nucleotidyltransferase

Guanylyltransferase

mRNA capping enzyme

Other

2.7.8: miscellaneous

Phosphatidyltransferases	CDP-diacylglycerol—glycerol-3-phosphate 3-phosphatidyltransferase CDP-diacylglycerol—serine O-phosphatidyltransferase CDP-diacylglycerol—inositol 3-phosphatidyltransferase CDP-diacylglycerol—choline O-phosphatidyltransferase

Glycosyl-1-phosphotransferase	N-acetylglucosamine-1-phosphate transferase

2.7.10-2.7.13: protein kinase
(PO₄; protein acceptor)

2.7.10: protein-tyrosine	see tyrosine kinases

2.7.11: protein-serine/threonine	see serine/threonine-specific protein kinases

2.7.12: protein-dual-specificity	see serine/threonine-specific protein kinases

2.7.13: protein-histidine	Protein-histidine pros-kinase Protein-histidine tele-kinase Histidine kinase

Enzymes

Activity	Active site Binding site Catalytic triad Oxyanion hole Enzyme promiscuity Catalytically perfect enzyme Coenzyme Cofactor Enzyme catalysis Enzyme kinetics Lineweaver–Burk plot Michaelis–Menten kinetics

Regulation	Allosteric regulation Cooperativity Enzyme inhibitor

Classification	EC number Enzyme superfamily Enzyme family List of enzymes

Types	EC1 Oxidoreductases(list) EC2 Transferases(list) EC3 Hydrolases(list) EC4 Lyases(list) EC5 Isomerases(list) EC6 Ligases(list)

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