Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
twitter

MetaCyc Reaction: 2.7.7.79

Superclasses: Reactions Classified By Conversion Type Simple Reactions Chemical Reactions
Reactions Classified By Substrate Macromolecule Reactions Polynucleotide-Reactions RNA-Reactions tRNA-Reactions

EC Number: 2.7.7.79

Enzymes and Genes:
tRNAHis guanylyltransferase Inferred from experiment : THG1 ( Saccharomyces cerevisiae )

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.

Mass balance status: Undetermined; a substrate lacks a chemical formula

Enzyme Commission Primary Name: tRNAHis guanylyltransferase

Enzyme Commission Synonyms: histidine tRNA guanylyltransferase, Thg1p (ambiguous), Thg1 (ambiguous)

Enzyme Commission Summary:
In eukarya an additional guanosine residue is added post-transcriptionally to the 5'-end of tRNAHis molecules. The addition occurs opposite a universally conserved adenosine73 and is thus the result of a non-templated 3'-5' addition reaction. The additional guanosine residue is an important determinant for aminoacylation by EC 6.1.1.21, histidyl-tRNA ligase. The enzyme requires a divalent cation for activity [Pande91]. ATP activation is not required when the substrate contains a 5-triphosphate (ppp-tRNAHis) [Gu03].

The enzyme catalyzes two successive reactions.

The overall reaction is:

p-tRNAHis + ATP + GTP = pppGp-tRNAHis + AMP + diphosphate.

Citations: [Jahn91, Placido10, Jackman08, Hyde10]

Gene-Reaction Schematic: ?

Relationship Links: BRENDA:EC:2.7.7.79 , ENZYME:EC:2.7.7.79 , IUBMB-ExplorEnz:EC:2.7.7.79

Credits:
Created 30-Jun-2011 by Kothari A , SRI International


References

Gu03: Gu W, Jackman JE, Lohan AJ, Gray MW, Phizicky EM (2003). "tRNAHis maturation: an essential yeast protein catalyzes addition of a guanine nucleotide to the 5' end of tRNAHis." Genes Dev 17(23);2889-901. PMID: 14633974

Hyde10: Hyde SJ, Eckenroth BE, Smith BA, Eberley WA, Heintz NH, Jackman JE, 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 U S A 107(47);20305-10. PMID: 21059936

Jackman08: Jackman JE, Phizicky EM (2008). "Identification of critical residues for G-1 addition and substrate recognition by tRNA(His) guanylyltransferase." Biochemistry 47(16);4817-25. PMID: 18366186

Jahn91: Jahn D, Pande S (1991). "Histidine tRNA guanylyltransferase from Saccharomyces cerevisiae. II. Catalytic mechanism." J Biol Chem 266(34);22832-6. PMID: 1660462

Pande91: Pande S, Jahn D, Soll D (1991). "Histidine tRNA guanylyltransferase from Saccharomyces cerevisiae. I. Purification and physical properties." J Biol Chem 266(34);22826-31. PMID: 1660461

Placido10: Placido A, Sieber F, Gobert A, Gallerani R, Giege P, Marechal-Drouard L (2010). "Plant mitochondria use two pathways for the biogenesis of tRNAHis." Nucleic Acids Res 38(21);7711-7. PMID: 20660484


Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
Page generated by SRI International Pathway Tools version 18.5 on Fri Nov 21, 2014, BIOCYC14A.