The domain within your query sequence starts at position 47 and ends at position 336; the E-value for the MTHFR domain shown below is 5.9e-121.

KMRRRMDSGDKWFSLEFFPPRTAEGAVNLISRFDRMAAGGPLFVDVTWHPAGDPGSDKET
SSMMIASTAVNYCGLETILHMTCCQQRPEEITGHLHRAKQLGLKNIMALRGDPVGDHWEA
EEGGFSYATDLVKHIRTEFADYFDICVAGYPRGHPDAESFEDDLKHLKEKVSAGADFIIT
QLFFEASTFFSFVKACTEIGISCPILPGIFPIQGYTSLRQLVKLSKLEVPQKIKDVIEPI
KDNDAAIRNYGIELAVSLCRELLDSGLVPGLHFYTLNREVATMEVLKQLG

MTHFR

MTHFR
PFAM accession number:PF02219
Interpro abstract (IPR003171): This family includes the 5,10-methylenetetrahydrofolate reductase from bacteria and methylenetetrahydrofolate reductase from eukaryotes (EC 1.5.1.20). The bacterial enzyme is a homotetramer and NADH is the preferred reductant while the eukaryotic enzyme is a homodimer and NADPH is the preferred reductant. In humans, there are several clinically significant mutations in MTHFR that result in hyperhomocysteinemia, which is a risk factor for the development of cardiovascular disease [(PUBMED:10201405)].
GO process:oxidation-reduction process (GO:0055114), methionine metabolic process (GO:0006555)
GO function:methylenetetrahydrofolate reductase (NAD(P)H) activity (GO:0004489)

This is a PFAM domain. For full annotation and more information, please see the PFAM entry MTHFR