Methionine transaminase
| Methionine transaminase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| EC no. | 2.6.1.88 | ||||||||
| Databases | |||||||||
| BRENDA | enzyme data | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | enzyme entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| Rhea | reactions | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| |||||||||
Methionine transaminase (EC 2.6.1.88, methionine-oxo-acid transaminase) is an enzyme with systematic name L-methionine:2-oxo-acid aminotransferase.[1] It catalyses a general chemical reaction that is used in the pathway to recycle the amino acid L-methionine:
- L-methionine + an α-keto acid 4-(methylthio)-2-oxobutanoic acid + an L-amino acid
The enzyme characterised from Klebsiella pneumoniae operates in the direction towards methionine and can use a variety of L-amino acids as amino group donors to react with 4-(methylthio)-2-oxobutanoic acid. L-tyrosine was found to be most effective.[2] A crystal structure of the corresponding enzyme in Escherichia coli has been determined.[3]
-2-oxobutanoic_acid.svg.png)
In plants such as Arabidopsis thaliana, the enzyme operates in the forward direction, as part of the pathway to glucosinolates which contain extra methylene groups (CH2) between the amino acid part and the thioether of methionine. These intermediates are formed from 4-(methylthio)-2-oxobutanoic acid.[4]
References
- ↑ Enzyme 2.6.1.88 at KEGG Pathway Database.
- ↑ Heilbronn J, Wilson J, Berger BJ (March 1999). "Tyrosine aminotransferase catalyzes the final step of methionine recycling in Klebsiella pneumoniae". Journal of Bacteriology. 181 (6): 1739–47. doi:10.1128/JB.181.6.1739-1747.1999. PMC 93571. PMID 10074065.
- ↑ Dolzan M, Johansson K, Roig-Zamboni V, Campanacci V, Tegoni M, Schneider G, Cambillau C (July 2004). "Crystal structure and reactivity of YbdL from Escherichia coli identify a methionine aminotransferase function". FEBS Letters. 571 (1–3): 141–6. Bibcode:2004FEBSL.571..141D. doi:10.1016/j.febslet.2004.06.075. PMID 15280032.
- ↑ Schuster J, Knill T, Reichelt M, Gershenzon J, Binder S (October 2006). "Branched-chain aminotransferase4 is part of the chain elongation pathway in the biosynthesis of methionine-derived glucosinolates in Arabidopsis". The Plant Cell. 18 (10): 2664–79. Bibcode:2006PlanC..18.2664S. doi:10.1105/tpc.105.039339. PMC 1626624. PMID 17056707.
External links
- Methionine+transaminase at the U.S. National Library of Medicine Medical Subject Headings (MeSH)