5-Methyltetrahydrofolate-homocysteine methyltransferase

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5-methyltetrahydrofolate-homocysteine methyltransferase
Identifiers
SymbolMTR
Entrez4548
HUGO7468
OMIM156570
RefSeqNM_000254
UniProtQ99707
Other data
EC number2.1.1.13
LocusChr. 1 q43

5-Methyltetrahydrofolate-homocysteine methyltransferase or (MTR) is an enzyme responsible for the production of methionine from homocysteine. MTR forms part of the S-adenosyl methionine cycle and is also called methionine synthase.[1]

Function

MTR contains the cofactor - methylcobalamin (MeB12) and uses the substrates N5-methyl-tetrahydrofolate (N5-methyl-THF) and homocysteine.

The enzyme works in two steps in a ping-pong reaction. First, methylcobalamin is formed by a methyl group transfer from N5-mTHF with formation of MeB12 and tetrahydrofolate (THF). In the second step, MeB12 transfers this methyl group to (homocysteine), regenerating the cofactor cobalamin and releasing the product methionine

File:VitaminB12 2.png
The MTR reaction


See also

References

  1. Banerjee RV, Matthews RG (1990). "Cobalamin-dependent methionine synthase" (PDF). FASEB J. 4 (5): 1450–9. PMID 2407589.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>

External links

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