Annotations: 1B5T

Domain Annotation: SCOP/SCOPe Classification SCOP-e Database Homepage

Chains	Domain Info	Class	Fold	Superfamily	Family	Domain	Species	Provenance Source (Version)
A	d1b5ta_	Alpha and beta proteins (a/b)	TIM beta/alpha-barrel	FAD-linked oxidoreductase	Methylenetetrahydrofolate reductase	Methylenetetrahydrofolate reductase	(Escherichia coli ) [TaxId: 562 ],	SCOPe (2.08)
B	d1b5tb_	Alpha and beta proteins (a/b)	TIM beta/alpha-barrel	FAD-linked oxidoreductase	Methylenetetrahydrofolate reductase	Methylenetetrahydrofolate reductase	(Escherichia coli ) [TaxId: 562 ],	SCOPe (2.08)
C	d1b5tc_	Alpha and beta proteins (a/b)	TIM beta/alpha-barrel	FAD-linked oxidoreductase	Methylenetetrahydrofolate reductase	Methylenetetrahydrofolate reductase	(Escherichia coli ) [TaxId: 562 ],	SCOPe (2.08)

Domain Annotation: SCOP2 Classification SCOP2 Database Homepage

Chains	Type	Family Name	Domain Identifier	Family Identifier	Provenance Source (Version)
A	SCOP2 Family	Methylenetetrahydrofolate reductase	8031494	4003348	SCOP2 (2022-06-29)
A	SCOP2 Superfamily	FAD-linked oxidoreductase	8043872	3000663	SCOP2 (2022-06-29)
B	SCOP2B Superfamily	FAD-linked oxidoreductase	8043872	3000663	SCOP2B (2022-06-29)
C	SCOP2B Superfamily	FAD-linked oxidoreductase	8043872	3000663	SCOP2B (2022-06-29)

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Family Name	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
A	MTHFR	e1b5tA1	A: a/b barrels	X: TIM beta/alpha-barrel	H: TIM barrels (From Topology)	T: TIM barrels	F: MTHFR	ECOD (1.6)
B	MTHFR	e1b5tB1	A: a/b barrels	X: TIM beta/alpha-barrel	H: TIM barrels (From Topology)	T: TIM barrels	F: MTHFR	ECOD (1.6)
C	MTHFR	e1b5tC1	A: a/b barrels	X: TIM beta/alpha-barrel	H: TIM barrels (From Topology)	T: TIM barrels	F: MTHFR	ECOD (1.6)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
A	3.20.20.220	Alpha Beta	Alpha-Beta Barrel	TIM Barrel		CATH (4.3.0)
B	3.20.20.220	Alpha Beta	Alpha-Beta Barrel	TIM Barrel		CATH (4.3.0)
C	3.20.20.220	Alpha Beta	Alpha-Beta Barrel	TIM Barrel		CATH (4.3.0)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
A, B, C	PF02219	Methylenetetrahydrofolate reductase (MTHFR)	Methylenetetrahydrofolate reductase	This family includes the 5,10-methylenetetrahydrofolate reductase EC:1.7.99.5 from bacteria and methylenetetrahydrofolate reductase EC: 1.5.1.20 from eukaryotes. The structure for this domain is known [1] to be a TIM barrel.	Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A, B, C	PROTEIN (METHYLENETETRAHYDROFOLATE REDUCTASE)	methylenetetrahydrofolate reductase (NADH) activity oxidoreductase activity methylenetetrahydrofolate reductase (NAD(P)H) activity oxidoreductase activity, acting on the CH-NH group of donors, NAD or NADP as acceptor oxidoreductase activity, acting on the CH-NH group of donors catalytic activity FAD binding flavin adenine dinucleotide binding binding nucleoside phosphate binding ion binding organic cyclic compound binding anion binding nucleotide binding methylenetetrahydrofolate reductase (NADH) activity oxidoreductase activity methylenetetrahydrofolate reductase (NAD(P)H) activity oxidoreductase activity, acting on the CH-NH group of donors, NAD or NADP as acceptor oxidoreductase activity, acting on the CH-NH group of donors catalytic activity FAD binding flavin adenine dinucleotide binding binding nucleoside phosphate binding ion binding organic cyclic compound binding anion binding nucleotide binding heterocyclic compound binding small molecule binding protein binding protein-folding chaperone binding	folic acid-containing compound metabolic process tetrahydrofolate interconversion modified amino acid metabolic process metabolic process cellular process small molecule metabolic process tetrahydrofolate metabolic process pteridine-containing compound metabolic process one-carbon metabolic process oxoacid metabolic process sulfur amino acid metabolic process aspartate family amino acid biosynthetic process aspartate family amino acid metabolic process amino acid metabolic process folic acid-containing compound metabolic process tetrahydrofolate interconversion modified amino acid metabolic process metabolic process cellular process small molecule metabolic process tetrahydrofolate metabolic process pteridine-containing compound metabolic process one-carbon metabolic process oxoacid metabolic process sulfur amino acid metabolic process aspartate family amino acid biosynthetic process aspartate family amino acid metabolic process amino acid metabolic process organic acid biosynthetic process organic acid metabolic process alpha-amino acid metabolic process carboxylic acid biosynthetic process sulfur compound metabolic process methionine biosynthetic process small molecule biosynthetic process carboxylic acid metabolic process L-amino acid biosynthetic process primary metabolic process methionine metabolic process L-amino acid metabolic process proteinogenic amino acid metabolic process amino acid biosynthetic process sulfur compound biosynthetic process biosynthetic process proteinogenic amino acid biosynthetic process sulfur amino acid biosynthetic process alpha-amino acid biosynthetic process	cellular anatomical structure intracellular anatomical structure cytoplasm cytosol protein-containing complex

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A, B, C	IPR003171	Methylenetetrahydrofolate reductase-like	Family
A, B, C	IPR029041	FAD-linked oxidoreductase-like	Homologous Superfamily
A, B, C	IPR004620	5,10-methylenetetrahydrofolate reductase	Family

RCSB PDB Core Operations are funded by the U.S. National Science Foundation (DBI-2321666), the US Department of Energy (DE-SC0019749), and the National Cancer Institute, National Institute of Allergy and Infectious Diseases, and National Institute of General Medical Sciences of the National Institutes of Health under grant R01GM157729.