1A4I

HUMAN TETRAHYDROFOLATE DEHYDROGENASE / CYCLOHYDROLASE

External Resource: Annotation

Domain Annotation: SCOP/SCOPe Classification
Domain Annotation: SCOP2 Classification
Domain Annotation: ECOD Classification
Domain Annotation: CATH
Protein Family Annotation
Gene Ontology: Gene Product Annotation
InterPro: Protein Family Classification
Pharos: Disease Associations
Structure Motif: Primary M-CSA Annotation

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

Chains	Domain Info	Class	Fold	Superfamily	Family	Domain	Species	Provenance Source (Version)
A	d1a4ia1	Alpha and beta proteins (a/b)	NAD(P)-binding Rossmann-fold domains	NAD(P)-binding Rossmann-fold domains	Aminoacid dehydrogenase-like, C-terminal domain	Methylenetetrahydrofolate dehydrogenase/cyclohydrolase	human (Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)
A	d1a4ia2	Alpha and beta proteins (a/b)	Aminoacid dehydrogenase-like, N-terminal domain	Aminoacid dehydrogenase-like, N-terminal domain	Tetrahydrofolate dehydrogenase/cyclohydrolase	Tetrahydrofolate dehydrogenase/cyclohydrolase	human (Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)
B	d1a4ib1	Alpha and beta proteins (a/b)	NAD(P)-binding Rossmann-fold domains	NAD(P)-binding Rossmann-fold domains	Aminoacid dehydrogenase-like, C-terminal domain	Methylenetetrahydrofolate dehydrogenase/cyclohydrolase	human (Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)
B	d1a4ib2	Alpha and beta proteins (a/b)	Aminoacid dehydrogenase-like, N-terminal domain	Aminoacid dehydrogenase-like, N-terminal domain	Tetrahydrofolate dehydrogenase/cyclohydrolase	Tetrahydrofolate dehydrogenase/cyclohydrolase	human (Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)

Domain Annotation: SCOP2 Classification SCOP2 Database Homepage

Chains	Type	Family Name	Domain Identifier	Family Identifier	Provenance Source (Version)
A	SCOP2B Superfamily	MtdA-like	8056181	3000046	SCOP2B (2022-06-29)
B	SCOP2 Family	FolD-like	8056180	4000102	SCOP2 (2022-06-29)
B	SCOP2 Superfamily	MtdA-like	8056181	3000046	SCOP2 (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	THF_DHG_CYH_C	e1a4iA1	A: a/b three-layered sandwiches	X: Rossmann-like	H: Rossmann-related	T: NAD(P)-binding Rossmann-fold domains	F: THF_DHG_CYH_C	ECOD (1.6)
A	THF_DHG_CYH	e1a4iA2	A: a/b three-layered sandwiches	X: Flavodoxin-like	H: Class I glutamine amidotransferase-like	T: Aminoacid dehydrogenase-like, N-terminal domain	F: THF_DHG_CYH	ECOD (1.6)
B	THF_DHG_CYH_C	e1a4iB1	A: a/b three-layered sandwiches	X: Rossmann-like	H: Rossmann-related	T: NAD(P)-binding Rossmann-fold domains	F: THF_DHG_CYH_C	ECOD (1.6)
B	THF_DHG_CYH	e1a4iB2	A: a/b three-layered sandwiches	X: Flavodoxin-like	H: Class I glutamine amidotransferase-like	T: Aminoacid dehydrogenase-like, N-terminal domain	F: THF_DHG_CYH	ECOD (1.6)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
A	3.40.50.720	Alpha Beta	3-Layer(aba) Sandwich	Rossmann fold	NAD(P)-binding Rossmann-like Domain	CATH (4.3.0)
A	3.40.50.10860	Alpha Beta	3-Layer(aba) Sandwich	Rossmann fold	Leucine Dehydrogenase, chain A, domain 1	CATH (4.3.0)
B	3.40.50.720	Alpha Beta	3-Layer(aba) Sandwich	Rossmann fold	NAD(P)-binding Rossmann-like Domain	CATH (4.3.0)
B	3.40.50.10860	Alpha Beta	3-Layer(aba) Sandwich	Rossmann fold	Leucine Dehydrogenase, chain A, domain 1	CATH (4.3.0)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
A, B	PF02882	Tetrahydrofolate dehydrogenase/cyclohydrolase, NAD(P)-binding domain (THF_DHG_CYH_C)	Tetrahydrofolate dehydrogenase/cyclohydrolase, NAD(P)-binding domain		Domain
A, B	PF00763	Tetrahydrofolate dehydrogenase/cyclohydrolase, catalytic domain (THF_DHG_CYH)	Tetrahydrofolate dehydrogenase/cyclohydrolase, catalytic domain		Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A, B	METHYLENETETRAHYDROFOLATE DEHYDROGENASE / METHENYLTETRAHYDROFOLATE CYCLOHYDROLASE	hydrolase activity, acting on carbon-nitrogen (but not peptide) bonds, in cyclic amidines cyclohydrolase activity methenyltetrahydrofolate cyclohydrolase activity hydrolase activity catalytic activity hydrolase activity, acting on carbon-nitrogen (but not peptide) bonds methylenetetrahydrofolate dehydrogenase (NADP+) activity oxidoreductase 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 methylenetetrahydrofolate dehydrogenase [NAD(P)+] activity binding adenyl ribonucleotide binding nucleotide binding hydrolase activity, acting on carbon-nitrogen (but not peptide) bonds, in cyclic amidines cyclohydrolase activity methenyltetrahydrofolate cyclohydrolase activity hydrolase activity catalytic activity hydrolase activity, acting on carbon-nitrogen (but not peptide) bonds methylenetetrahydrofolate dehydrogenase (NADP+) activity oxidoreductase 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 methylenetetrahydrofolate dehydrogenase [NAD(P)+] activity binding adenyl ribonucleotide binding nucleotide binding purine ribonucleotide binding purine ribonucleoside triphosphate binding nucleoside phosphate binding ion binding purine nucleotide binding anion binding adenyl nucleotide binding ATP binding heterocyclic compound binding carbohydrate derivative binding ribonucleotide binding small molecule binding methylenetetrahydrofolate dehydrogenase (NAD+) activity formate-tetrahydrofolate ligase activity ligase activity, forming carbon-nitrogen bonds ligase activity	developmental process heart development multicellular organism development multicellular organismal process anatomical structure development animal organ development circulatory system development system development embryonic organ morphogenesis embryonic viscerocranium morphogenesis embryonic cranial skeleton morphogenesis chordate embryonic development embryonic morphogenesis embryo development developmental process heart development multicellular organism development multicellular organismal process anatomical structure development animal organ development circulatory system development system development embryonic organ morphogenesis embryonic viscerocranium morphogenesis embryonic cranial skeleton morphogenesis chordate embryonic development embryonic morphogenesis embryo development anatomical structure morphogenesis embryo development ending in birth or egg hatching skeletal system development cranial skeletal system development animal organ morphogenesis embryonic skeletal system development skeletal system morphogenesis embryonic organ development embryonic skeletal system morphogenesis ribose phosphate metabolic process nucleotide biosynthetic process carbohydrate derivative metabolic process purine ribonucleotide biosynthetic process nucleobase-containing compound metabolic process ribonucleotide biosynthetic process purine nucleotide metabolic process ribonucleotide metabolic process nucleobase-containing small molecule metabolic process purine-containing compound biosynthetic process phosphate-containing compound metabolic process small molecule metabolic process phosphorus metabolic process ribose phosphate biosynthetic process nucleoside phosphate metabolic process carbohydrate derivative biosynthetic process primary metabolic process nucleotide metabolic process nucleobase-containing compound biosynthetic process purine-containing compound metabolic process biosynthetic process organophosphate metabolic process organophosphate biosynthetic process nucleoside phosphate biosynthetic process metabolic process cellular process purine ribonucleotide metabolic process purine nucleotide biosynthetic process folic acid-containing compound metabolic process tetrahydrofolate interconversion modified amino acid 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 metabolic process carboxylic acid metabolic process amino acid metabolic process methionine metabolic process organic acid metabolic process alpha-amino acid metabolic process L-amino acid metabolic process proteinogenic amino acid metabolic process sulfur compound metabolic process 10-formyltetrahydrofolate metabolic process folic acid-containing compound biosynthetic process small molecule biosynthetic process dicarboxylic acid metabolic process modified amino acid biosynthetic process organic acid biosynthetic process carboxylic acid biosynthetic process 10-formyltetrahydrofolate biosynthetic process pteridine-containing compound biosynthetic process tetrahydrofolate biosynthetic process dicarboxylic acid biosynthetic process embryonic epithelial tube formation tube formation epithelial tube formation tube morphogenesis primary neural tube formation epithelial tube morphogenesis morphogenesis of embryonic epithelium epithelium development neural tube development tube development morphogenesis of an epithelium nervous system development tissue development tissue morphogenesis neural tube closure neural tube formation anatomical structure formation involved in morphogenesis tube closure homocysteine metabolic process serine family amino acid metabolic process transsulfuration cysteine metabolic process non-proteinogenic amino acid metabolic process homoserine metabolic process aspartate family amino acid biosynthetic process methionine biosynthetic process L-amino acid biosynthetic process amino acid biosynthetic process sulfur compound biosynthetic process proteinogenic amino acid biosynthetic process sulfur amino acid biosynthetic process alpha-amino acid biosynthetic process embryonic neurocranium morphogenesis multicellular organismal-level homeostasis leukocyte homeostasis homeostatic process immune system process homeostasis of number of cells myeloid cell homeostasis neutrophil homeostasis serine family amino acid biosynthetic process somite development	membrane-bounded organelle intracellular organelle cellular anatomical structure intracellular anatomical structure mitochondrion organelle cytoplasm intracellular membrane-bounded organelle membrane extracellular exosome extracellular vesicle extracellular organelle extracellular region extracellular space membrane-bounded organelle intracellular organelle cellular anatomical structure intracellular anatomical structure mitochondrion organelle cytoplasm intracellular membrane-bounded organelle membrane extracellular exosome extracellular vesicle extracellular organelle extracellular region extracellular space vesicle extracellular membrane-bounded organelle cytosol

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A, B	IPR046346	Aminoacid dehydrogenase-like, N-terminal domain superfamily	Homologous Superfamily
A, B	IPR020630	Tetrahydrofolate dehydrogenase/cyclohydrolase, catalytic domain	Domain
A, B	IPR000672	Tetrahydrofolate dehydrogenase/cyclohydrolase	Family
A, B	IPR027417	P-loop containing nucleoside triphosphate hydrolase	Homologous Superfamily
A, B	IPR020631	Tetrahydrofolate dehydrogenase/cyclohydrolase, NAD(P)-binding domain	Domain
A, B	IPR000559	Formate-tetrahydrofolate ligase, FTHFS	Family
A, B	IPR036291	NAD(P)-binding domain superfamily	Homologous Superfamily
A, B	IPR020628	Formate-tetrahydrofolate ligase, FTHFS, conserved site	Conserved Site
A, B	IPR020867	Tetrahydrofolate dehydrogenase/cyclohydrolase, conserved site	Conserved Site

Pharos: Disease Associations Pharos Homepage Annotation

Chains	Drug Target	Associated Disease
A, B	Pharos: P11586	neural tube defect neural tube defects, folate-sensitive schizophrenia Spinal Cord Myelodysplasia tuberculosis colorectal cancer diastematomyelia iniencephaly pancreatic ductal adenocarcinoma combined immunodeficiency and megaloblastic anemia with or without hyperhomocysteinemia ductal breast carcinoma in situ lung cancer neurenteric cyst placental abruption tethered spinal cord syndrome neural tube defect neural tube defects, folate-sensitive schizophrenia Spinal Cord Myelodysplasia tuberculosis colorectal cancer diastematomyelia iniencephaly pancreatic ductal adenocarcinoma combined immunodeficiency and megaloblastic anemia with or without hyperhomocysteinemia ductal breast carcinoma in situ lung cancer neurenteric cyst placental abruption tethered spinal cord syndrome bipolar disorder craniorachischisis lymphoplasmacytic lymphoma ovarian cancer

Structure Motif Annotation: Mechanism and Catalytic Site Atlas M-CSA Database Homepage

Chains	Enzyme Name	Description	Catalytic Residues
A	methylenetetrahydrofolate dehydrogenase (NADP+) M-CSA #389	Enzymes involved in tetrahydrofolate metabolism are of particular pharmaceutical interest, as their function is crucial for amino acid and DNA biosynthesis. In eukaryotes, the enzyme that performs this reaction occurs as a trifunctional enzyme that also has methylenetetrahydrofolate dehydrogenase (NADP+) (EC 1.5.1.5) and formate-tetrahydrofolate ligase (EC 6.3.4.3) activity. In some prokaryotes, it occurs as a bifunctional enzyme that also has dehydrogenase (EC 1.5.1.5) activity or formiminotetrahydrofolate cyclodeaminase (EC 4.3.1.4) activity. This particular entry represents the dehydrogenase activity. Although the human protein represented here is actually trifunctional, the representative PDB structure only contains the dehydrogenase (D) and cyclohydrolase (C) domains, which have an overlapping active site (as determined by chemical modification and kinetic studies).	Defined by 3 residues: LYS:A-56GLN:A-100ASP:A-125 \| Explore in 3D: M-CSA Motif Definition Search M-CSA Motif EC: 1.5.1.5 (PDB Primary Data) Search M-CSA Motif + EC 1.5.1.5 EC: 3.5.4.9 (PDB Primary Data) Search M-CSA Motif + EC 3.5.4.9 EC: 6.3.4.3 (UniProt) Search M-CSA Motif + EC 6.3.4.3
A	methenyltetrahydrofolate cyclohydrolase M-CSA #458	Enzymes involved in tetrahydrofolate metabolism are of particular pharmaceutical interest, as their function is crucial for amino acid and DNA biosynthesis. In eukaryotes, the enzyme that performs this reaction occurs as a trifunctional enzyme that has two active sites: the bifunctional enzyme methylenetetrahydrofolate dehydrogenase – cyclohydrolase catalyses two sequential reactions involved in the interconversion of substituted tetrahydrofolates. The interconversion of 5,10-methylene-H4folate with 5,10-methenyl-H4folate is accomplished through the NADP+-dependent dehydrogenase activity, whereas 5,10-methenyl-H4folate and 10-formyl-H4folate are interconverted by the cyclohydrolase activity. The second domain represents the formate-tetrahydrofolate ligase (EC 6.3.4.3) activity. Although the human protein represented here is actually trifunctional, the representative PDB structure only contains the dehydrogenase (D) and cyclohydrolase (C) domains, which have an overlapping active site (as determined by chemical modification and kinetic studies). This entry represents the bifunctional activity.	Defined by 3 residues: SER:A-49LYS:A-56GLN:A-100 \| Explore in 3D: M-CSA Motif Definition Search M-CSA Motif EC: 1.5.1.5 (PDB Primary Data) Search M-CSA Motif + EC 1.5.1.5 EC: 3.5.4.9 (PDB Primary Data) Search M-CSA Motif + EC 3.5.4.9 EC: 6.3.4.3 (UniProt) Search M-CSA Motif + EC 6.3.4.3

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.