MTRR
5-methyltetrahydrofolate-homocysteine methyltransferase reductase
Pathway candidate — not linked to PFS or PSSD by any record here
Gene summary
A protein-coding gene on chromosome 5 (methylation and one-carbon metabolism). Encodes a member of the ferredoxin-NADP(+) reductase (FNR) family of electron transferases. This protein functions in the synthesis of methionine by regenerating methionine synthase to a functional state.
Source: NCBI Gene, accessed 2026-10-07.
Protein reference (UniProt)
- Protein
Methionine synthase reductase
- Function (excerpt)
Key enzyme in methionine and folate homeostasis responsible for the reactivation of methionine synthase (MTR/MS) activity by catalyzing the reductive methylation of MTR-bound cob(II)alamin. Cobalamin (vitamin B12) forms a complex with MTR to serve as an intermediary in methyl transfer reactions that cycles between MTR-bound methylcob(III)alamin and MTR bound-cob(I)alamin forms, and occasional oxidative escape of the cob(I)alamin intermediate during the catalytic cycle leads to the inactive cob(II)alamin species (Probable). The processing of cobalamin in the cytosol occurs in a multiprotein complex composed of at least MMACHC, MMADHC, MTRR and MTR which may contribute to shuttle safely and efficiently cobalamin towards MTR in order to produce methionine. Also necessary for the utilization of methyl groups from the folate cycle, thereby affecting transgenerational epigenetic inheritance (By similarity).
- Subcellular location
Cytoplasm.
- Tissue specificity
Found in all tissues tested, particularly abundant in skeletal muscle.
- Associated conditions
Homocystinuria-megaloblastic anemia, cblE type (HMAE); Neural tube defects, folate-sensitive (NTDFS).
Source: UniProtKB/Swiss-Prot Q9UBK8, release 2026_03, licensed CC BY 4.0. This is the protein’s normal biology, not evidence about post-drug syndromes; associated conditions are inherited disorders of the gene, not PFS, PSSD or PRSD.
Why its pathway is in the library
One-carbon metabolism supplies methyl groups for DNA/histone methylation — the epigenetic layer implicated in persistent post-drug changes.
Written for the whole methylation / one-carbon family, not for MTRR specifically.
Mentioned in 0 corpus records
No corpus record names MTRR directly yet. It is in the library because it sits in a pathway the corpus tracks (Methylation / one-carbon).
Also in methylation and one-carbon metabolism
All 5 genes- MTHFRPowers
methylenetetrahydrofolate reductase
chr 1· Methylation / one-carbon· 4 records - AHCY
adenosylhomocysteinase
chr 20· Methylation / one-carbon· Pathway candidate - BHMT
betaine--homocysteine S-methyltransferase
chr 5· Methylation / one-carbon· Pathway candidate - MTR
5-methyltetrahydrofolate-homocysteine methyltransferase
chr 1· Methylation / one-carbon· Pathway candidate
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