Figure 1. Homocysteine metabolic pathways.
Products of the enzymatic pathways are shown in rectangles, co-factors
are shown in circles, and enzymes are in text. The genes coding for the
enzymes included in this study are shown as underlined text.
Abbreviations: B12, vitamin B12; BHMT,
betaine-homocysteine methyltransferase; CBS, cystathionine beta
synthase; DHF, dihydrofolate; DHFR, dihydrofolate
reductase; dTMP, thymidine monophosphate; dUMP, uridine
monophosphate; FAD, flavin adenine dinucleotide; GLY,
glycine; MTHFD1, trifunctional methylenetetrahydrofolate
dehydrogenase, cyclohydrolase, synthase; MTHFR,
methylenetetrahydrofolate reductase; MTR,
5-methyltetrahydrofolate-homocysteine methyltransferase; MTRR,
5-methyltetrahydrofolate-homocysteine methyltransferase reductase; MT,
methyl transferase; SAH, S-adenosylhomocysteine hydrolase; SER,
serine; THF, tetrahydrofolate; TS, thymidylate
synthase; 5-CH3-THF, 5-methyl tetrahydrofolate; 5,10-CH2=THF,
methylene tetrahydrofolate; 5,10=CH2-THF, methenyl
tetrahydrofolate; 10-CHO-THF, 10-formyl tetrahydrofolate.