3DVA

Snapshots of catalysis in the E1 subunit of the pyruvate dehydrogenase multi-enzyme complex

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

Domain Annotation: SCOP/SCOPe Classification SCOP Database Homepage

Chains	Domain Info	Class	Fold	Superfamily	Family	Domain	Species	Provenance Source (Version)
A	d3dvaa_	Alpha and beta proteins (a/b)	Thiamin diphosphate-binding fold (THDP-binding)	Thiamin diphosphate-binding fold (THDP-binding)	Branched-chain alpha-keto acid dehydrogenase PP module	automated matches	(Geobacillus stearothermophilus ) [TaxId: 1422 ],	SCOPe (2.08)
C	d3dvac_	Alpha and beta proteins (a/b)	Thiamin diphosphate-binding fold (THDP-binding)	Thiamin diphosphate-binding fold (THDP-binding)	Branched-chain alpha-keto acid dehydrogenase PP module	automated matches	(Geobacillus stearothermophilus ) [TaxId: 1422 ],	SCOPe (2.08)
E	d3dvae_	Alpha and beta proteins (a/b)	Thiamin diphosphate-binding fold (THDP-binding)	Thiamin diphosphate-binding fold (THDP-binding)	Branched-chain alpha-keto acid dehydrogenase PP module	automated matches	(Geobacillus stearothermophilus ) [TaxId: 1422 ],	SCOPe (2.08)
G	d3dvag_	Alpha and beta proteins (a/b)	Thiamin diphosphate-binding fold (THDP-binding)	Thiamin diphosphate-binding fold (THDP-binding)	Branched-chain alpha-keto acid dehydrogenase PP module	automated matches	(Geobacillus stearothermophilus ) [TaxId: 1422 ],	SCOPe (2.08)
B	d3dvab1	Alpha and beta proteins (a/b)	Thiamin diphosphate-binding fold (THDP-binding)	Thiamin diphosphate-binding fold (THDP-binding)	automated matches	automated matches	(Geobacillus stearothermophilus ) [TaxId: 1422 ],	SCOPe (2.08)
B	d3dvab2	Alpha and beta proteins (a/b)	TK C-terminal domain-like	TK C-terminal domain-like	automated matches	automated matches	(Geobacillus stearothermophilus ) [TaxId: 1422 ],	SCOPe (2.08)
D	d3dvad1	Alpha and beta proteins (a/b)	Thiamin diphosphate-binding fold (THDP-binding)	Thiamin diphosphate-binding fold (THDP-binding)	automated matches	automated matches	(Geobacillus stearothermophilus ) [TaxId: 1422 ],	SCOPe (2.08)
D	d3dvad2	Alpha and beta proteins (a/b)	TK C-terminal domain-like	TK C-terminal domain-like	automated matches	automated matches	(Geobacillus stearothermophilus ) [TaxId: 1422 ],	SCOPe (2.08)
F	d3dvaf1	Alpha and beta proteins (a/b)	Thiamin diphosphate-binding fold (THDP-binding)	Thiamin diphosphate-binding fold (THDP-binding)	automated matches	automated matches	(Geobacillus stearothermophilus ) [TaxId: 1422 ],	SCOPe (2.08)
F	d3dvaf2	Alpha and beta proteins (a/b)	TK C-terminal domain-like	TK C-terminal domain-like	automated matches	automated matches	(Geobacillus stearothermophilus ) [TaxId: 1422 ],	SCOPe (2.08)
H	d3dvah1	Alpha and beta proteins (a/b)	Thiamin diphosphate-binding fold (THDP-binding)	Thiamin diphosphate-binding fold (THDP-binding)	automated matches	automated matches	(Geobacillus stearothermophilus ) [TaxId: 1422 ],	SCOPe (2.08)
H	d3dvah2	Alpha and beta proteins (a/b)	TK C-terminal domain-like	TK C-terminal domain-like	automated matches	automated matches	(Geobacillus stearothermophilus ) [TaxId: 1422 ],	SCOPe (2.08)
I	d3dvai_	All alpha proteins	Peripheral subunit-binding domain of 2-oxo acid dehydrogenase complex	Peripheral subunit-binding domain of 2-oxo acid dehydrogenase complex	automated matches	automated matches	(Geobacillus stearothermophilus ) [TaxId: 1422 ],	SCOPe (2.08)
J	d3dvaj_	All alpha proteins	Peripheral subunit-binding domain of 2-oxo acid dehydrogenase complex	Peripheral subunit-binding domain of 2-oxo acid dehydrogenase complex	automated matches	automated matches	(Geobacillus stearothermophilus ) [TaxId: 1422 ],	SCOPe (2.08)

Domain Annotation: SCOP2 Classification SCOP2 Database Homepage

Chains	Type	Family Name	Domain Identifier	Family Identifier	Provenance Source (Version)
A	SCOP2B Superfamily	Thiamin diphosphate-binding fold (THDP-binding)	8043326	3001790	SCOP2B (2022-06-29)
C	SCOP2B Superfamily	Thiamin diphosphate-binding fold (THDP-binding)	8043326	3001790	SCOP2B (2022-06-29)
E	SCOP2B Superfamily	Thiamin diphosphate-binding fold (THDP-binding)	8043326	3001790	SCOP2B (2022-06-29)
G	SCOP2B Superfamily	Thiamin diphosphate-binding fold (THDP-binding)	8043326	3001790	SCOP2B (2022-06-29)
B	SCOP2B Superfamily	Thiamin diphosphate-binding fold (THDP-binding)	8043324	3001790	SCOP2B (2022-06-29)
B	SCOP2B Superfamily	TK C-terminal domain-like	8043325	3000424	SCOP2B (2022-06-29)
D	SCOP2B Superfamily	TK C-terminal domain-like	8043325	3000424	SCOP2B (2022-06-29)
D	SCOP2B Superfamily	Thiamin diphosphate-binding fold (THDP-binding)	8043324	3001790	SCOP2B (2022-06-29)
F	SCOP2B Superfamily	TK C-terminal domain-like	8043325	3000424	SCOP2B (2022-06-29)
F	SCOP2B Superfamily	Thiamin diphosphate-binding fold (THDP-binding)	8043324	3001790	SCOP2B (2022-06-29)
H	SCOP2B Superfamily	Thiamin diphosphate-binding fold (THDP-binding)	8043324	3001790	SCOP2B (2022-06-29)
H	SCOP2B Superfamily	TK C-terminal domain-like	8043325	3000424	SCOP2B (2022-06-29)
I	SCOP2B Superfamily	Peripheral subunit-binding domain of 2-oxo acid dehydrogenase complex	8043331	3001183	SCOP2B (2022-06-29)
J	SCOP2B Superfamily	Peripheral subunit-binding domain of 2-oxo acid dehydrogenase complex	8043331	3001183	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	E1_dh	e3dvaA1	A: a/b three-layered sandwiches	X: Thiamin diphosphate-binding fold (THDP-binding) (From Topology)	H: Thiamin diphosphate-binding fold (THDP-binding) (From Topology)	T: Thiamin diphosphate-binding fold (THDP-binding)	F: E1_dh	ECOD (1.6)
C	E1_dh	e3dvaC1	A: a/b three-layered sandwiches	X: Thiamin diphosphate-binding fold (THDP-binding) (From Topology)	H: Thiamin diphosphate-binding fold (THDP-binding) (From Topology)	T: Thiamin diphosphate-binding fold (THDP-binding)	F: E1_dh	ECOD (1.6)
E	E1_dh	e3dvaE1	A: a/b three-layered sandwiches	X: Thiamin diphosphate-binding fold (THDP-binding) (From Topology)	H: Thiamin diphosphate-binding fold (THDP-binding) (From Topology)	T: Thiamin diphosphate-binding fold (THDP-binding)	F: E1_dh	ECOD (1.6)
G	E1_dh	e3dvaG1	A: a/b three-layered sandwiches	X: Thiamin diphosphate-binding fold (THDP-binding) (From Topology)	H: Thiamin diphosphate-binding fold (THDP-binding) (From Topology)	T: Thiamin diphosphate-binding fold (THDP-binding)	F: E1_dh	ECOD (1.6)
B	Transketolase_C	e3dvaB3	A: a/b three-layered sandwiches	X: TK C-terminal domain-like (From Topology)	H: TK C-terminal domain-like (From Topology)	T: TK C-terminal domain-like	F: Transketolase_C	ECOD (1.6)
B	Transket_pyr	e3dvaB4	A: a/b three-layered sandwiches	X: Thiamin diphosphate-binding fold (THDP-binding) (From Topology)	H: Thiamin diphosphate-binding fold (THDP-binding) (From Topology)	T: Thiamin diphosphate-binding fold (THDP-binding)	F: Transket_pyr	ECOD (1.6)
D	Transketolase_C	e3dvaD3	A: a/b three-layered sandwiches	X: TK C-terminal domain-like (From Topology)	H: TK C-terminal domain-like (From Topology)	T: TK C-terminal domain-like	F: Transketolase_C	ECOD (1.6)
D	Transket_pyr	e3dvaD4	A: a/b three-layered sandwiches	X: Thiamin diphosphate-binding fold (THDP-binding) (From Topology)	H: Thiamin diphosphate-binding fold (THDP-binding) (From Topology)	T: Thiamin diphosphate-binding fold (THDP-binding)	F: Transket_pyr	ECOD (1.6)
F	Transketolase_C	e3dvaF1	A: a/b three-layered sandwiches	X: TK C-terminal domain-like (From Topology)	H: TK C-terminal domain-like (From Topology)	T: TK C-terminal domain-like	F: Transketolase_C	ECOD (1.6)
F	Transket_pyr	e3dvaF2	A: a/b three-layered sandwiches	X: Thiamin diphosphate-binding fold (THDP-binding) (From Topology)	H: Thiamin diphosphate-binding fold (THDP-binding) (From Topology)	T: Thiamin diphosphate-binding fold (THDP-binding)	F: Transket_pyr	ECOD (1.6)
H	Transketolase_C	e3dvaH1	A: a/b three-layered sandwiches	X: TK C-terminal domain-like (From Topology)	H: TK C-terminal domain-like (From Topology)	T: TK C-terminal domain-like	F: Transketolase_C	ECOD (1.6)
H	Transket_pyr	e3dvaH2	A: a/b three-layered sandwiches	X: Thiamin diphosphate-binding fold (THDP-binding) (From Topology)	H: Thiamin diphosphate-binding fold (THDP-binding) (From Topology)	T: Thiamin diphosphate-binding fold (THDP-binding)	F: Transket_pyr	ECOD (1.6)
I	E3_binding	e3dvaI1	A: alpha arrays	X: Peripheral subunit-binding domain of 2-oxo acid dehydrogenase complex (From Topology)	H: Peripheral subunit-binding domain of 2-oxo acid dehydrogenase complex (From Topology)	T: Peripheral subunit-binding domain of 2-oxo acid dehydrogenase complex	F: E3_binding	ECOD (1.6)
J	E3_binding	e3dvaJ1	A: alpha arrays	X: Peripheral subunit-binding domain of 2-oxo acid dehydrogenase complex (From Topology)	H: Peripheral subunit-binding domain of 2-oxo acid dehydrogenase complex (From Topology)	T: Peripheral subunit-binding domain of 2-oxo acid dehydrogenase complex	F: E3_binding	ECOD (1.6)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
A	3.40.50.970	Alpha Beta	3-Layer(aba) Sandwich	Rossmann fold	Thiamin diphosphate (ThDP)-binding fold, Pyr/PP domains	CATH (4.3.0)
C	3.40.50.970	Alpha Beta	3-Layer(aba) Sandwich	Rossmann fold	Thiamin diphosphate (ThDP)-binding fold, Pyr/PP domains	CATH (4.3.0)
E	3.40.50.970	Alpha Beta	3-Layer(aba) Sandwich	Rossmann fold	Thiamin diphosphate (ThDP)-binding fold, Pyr/PP domains	CATH (4.3.0)
G	3.40.50.970	Alpha Beta	3-Layer(aba) Sandwich	Rossmann fold	Thiamin diphosphate (ThDP)-binding fold, Pyr/PP domains	CATH (4.3.0)
B	3.40.50.970	Alpha Beta	3-Layer(aba) Sandwich	Rossmann fold	Thiamin diphosphate (ThDP)-binding fold, Pyr/PP domains	CATH (4.3.0)
B	3.40.50.920	Alpha Beta	3-Layer(aba) Sandwich	Rossmann fold		CATH (4.3.0)
D	3.40.50.970	Alpha Beta	3-Layer(aba) Sandwich	Rossmann fold	Thiamin diphosphate (ThDP)-binding fold, Pyr/PP domains	CATH (4.3.0)
D	3.40.50.920	Alpha Beta	3-Layer(aba) Sandwich	Rossmann fold		CATH (4.3.0)
F	3.40.50.970	Alpha Beta	3-Layer(aba) Sandwich	Rossmann fold	Thiamin diphosphate (ThDP)-binding fold, Pyr/PP domains	CATH (4.3.0)
F	3.40.50.920	Alpha Beta	3-Layer(aba) Sandwich	Rossmann fold		CATH (4.3.0)
H	3.40.50.970	Alpha Beta	3-Layer(aba) Sandwich	Rossmann fold	Thiamin diphosphate (ThDP)-binding fold, Pyr/PP domains	CATH (4.3.0)
H	3.40.50.920	Alpha Beta	3-Layer(aba) Sandwich	Rossmann fold		CATH (4.3.0)
I	4.10.320.10	Few Secondary Structures	Irregular	Dihydrolipoamide Transferase	E3-binding domain	CATH (4.3.0)
J	4.10.320.10	Few Secondary Structures	Irregular	Dihydrolipoamide Transferase	E3-binding domain	CATH (4.3.0)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
A, C, E, G	PF00676	Dehydrogenase E1 component (E1_dh)	Dehydrogenase E1 component	-	Family
B, D, F, H	PF02779	Transketolase, pyrimidine binding domain (Transket_pyr)	Transketolase, pyrimidine binding domain	This family includes transketolase enzymes, pyruvate dehydrogenases, and branched chain alpha-keto acid decarboxylases.	Domain
B, D, F, H	PF02780	Transketolase, C-terminal domain (Transketolase_C)	Transketolase, C-terminal domain	The C-terminal domain of transketolase has been proposed as a regulatory molecule binding site [2].	Domain
I, J	PF02817	e3 binding domain (E3_binding)	e3 binding domain	-	Family

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A, C, E, G	Pyruvate dehydrogenase E1 component subunit alpha	oxidoreductase activity, acting on the aldehyde or oxo group of donors, disulfide as acceptor oxidoreductase activity pyruvate dehydrogenase (acetyl-transferring) activity oxidoreductase activity, acting on the aldehyde or oxo group of donors pyruvate dehydrogenase activity catalytic activity	ribonucleotide catabolic process pyridine nucleotide catabolic process oxoacid metabolic process carbohydrate catabolic process carbohydrate derivative metabolic process organophosphate catabolic process nucleoside phosphate catabolic process organic acid metabolic process nucleobase-containing compound metabolic process glycolytic process phosphate-containing compound metabolic process pyridine-containing compound metabolic process small molecule metabolic process purine ribonucleotide catabolic process ribonucleotide catabolic process pyridine nucleotide catabolic process oxoacid metabolic process carbohydrate catabolic process carbohydrate derivative metabolic process organophosphate catabolic process nucleoside phosphate catabolic process organic acid metabolic process nucleobase-containing compound metabolic process glycolytic process phosphate-containing compound metabolic process pyridine-containing compound metabolic process small molecule metabolic process purine ribonucleotide catabolic process phosphorus metabolic process pyridine nucleotide metabolic process nucleoside phosphate metabolic process organonitrogen compound catabolic process nicotinamide nucleotide metabolic process pyruvate metabolic process cellular metabolic process purine nucleoside diphosphate metabolic process primary metabolic process purine-containing compound catabolic process nucleotide metabolic process nucleobase-containing compound catabolic process organic cyclic compound metabolic process nucleoside diphosphate metabolic process purine nucleoside diphosphate catabolic process nucleoside diphosphate catabolic process metabolic process nucleoside triphosphate metabolic process monocarboxylic acid metabolic process purine ribonucleotide metabolic process pyridine-containing compound catabolic process ribose phosphate metabolic process catabolic process ATP metabolic process purine nucleotide metabolic process organic substance metabolic process ribonucleotide metabolic process nucleobase-containing small molecule metabolic process purine ribonucleoside triphosphate metabolic process ribonucleoside diphosphate metabolic process ribonucleoside diphosphate catabolic process nucleotide catabolic process ribonucleoside triphosphate metabolic process purine nucleoside triphosphate metabolic process purine nucleotide catabolic process carbohydrate metabolic process carbohydrate derivative catabolic process organonitrogen compound metabolic process ADP catabolic process carboxylic acid metabolic process generation of precursor metabolites and energy organic cyclic compound catabolic process purine-containing compound metabolic process ADP metabolic process organophosphate metabolic process purine ribonucleoside diphosphate metabolic process cellular process organic substance catabolic process purine ribonucleoside diphosphate catabolic process	-
B, D, F, H	Pyruvate dehydrogenase E1 component subunit beta	oxidoreductase activity, acting on the aldehyde or oxo group of donors, disulfide as acceptor oxidoreductase activity pyruvate dehydrogenase (acetyl-transferring) activity oxidoreductase activity, acting on the aldehyde or oxo group of donors pyruvate dehydrogenase activity catalytic activity	ribonucleotide catabolic process pyridine nucleotide catabolic process oxoacid metabolic process carbohydrate catabolic process carbohydrate derivative metabolic process organophosphate catabolic process nucleoside phosphate catabolic process organic acid metabolic process nucleobase-containing compound metabolic process glycolytic process phosphate-containing compound metabolic process pyridine-containing compound metabolic process small molecule metabolic process purine ribonucleotide catabolic process ribonucleotide catabolic process pyridine nucleotide catabolic process oxoacid metabolic process carbohydrate catabolic process carbohydrate derivative metabolic process organophosphate catabolic process nucleoside phosphate catabolic process organic acid metabolic process nucleobase-containing compound metabolic process glycolytic process phosphate-containing compound metabolic process pyridine-containing compound metabolic process small molecule metabolic process purine ribonucleotide catabolic process phosphorus metabolic process pyridine nucleotide metabolic process nucleoside phosphate metabolic process organonitrogen compound catabolic process nicotinamide nucleotide metabolic process pyruvate metabolic process cellular metabolic process purine nucleoside diphosphate metabolic process primary metabolic process purine-containing compound catabolic process nucleotide metabolic process nucleobase-containing compound catabolic process organic cyclic compound metabolic process nucleoside diphosphate metabolic process purine nucleoside diphosphate catabolic process nucleoside diphosphate catabolic process metabolic process nucleoside triphosphate metabolic process monocarboxylic acid metabolic process purine ribonucleotide metabolic process pyridine-containing compound catabolic process ribose phosphate metabolic process catabolic process ATP metabolic process purine nucleotide metabolic process organic substance metabolic process ribonucleotide metabolic process nucleobase-containing small molecule metabolic process purine ribonucleoside triphosphate metabolic process ribonucleoside diphosphate metabolic process ribonucleoside diphosphate catabolic process nucleotide catabolic process ribonucleoside triphosphate metabolic process purine nucleoside triphosphate metabolic process purine nucleotide catabolic process carbohydrate metabolic process carbohydrate derivative catabolic process organonitrogen compound metabolic process ADP catabolic process carboxylic acid metabolic process generation of precursor metabolites and energy organic cyclic compound catabolic process purine-containing compound metabolic process ADP metabolic process organophosphate metabolic process purine ribonucleoside diphosphate metabolic process cellular process organic substance catabolic process purine ribonucleoside diphosphate catabolic process	-
I, J	Dihydrolipoyllysine-residue acetyltransferase component of pyruvate dehydrogenase complex	acetyltransferase activity catalytic activity, acting on a protein acyltransferase activity dihydrolipoyllysine-residue acetyltransferase activity acyltransferase activity, transferring groups other than amino-acyl groups transferase activity S-acetyltransferase activity S-acyltransferase activity catalytic activity	ribonucleotide catabolic process pyridine nucleotide catabolic process oxoacid metabolic process carbohydrate catabolic process carbohydrate derivative metabolic process organophosphate catabolic process nucleoside phosphate catabolic process organic acid metabolic process nucleobase-containing compound metabolic process glycolytic process phosphate-containing compound metabolic process pyridine-containing compound metabolic process small molecule metabolic process purine ribonucleotide catabolic process ribonucleotide catabolic process pyridine nucleotide catabolic process oxoacid metabolic process carbohydrate catabolic process carbohydrate derivative metabolic process organophosphate catabolic process nucleoside phosphate catabolic process organic acid metabolic process nucleobase-containing compound metabolic process glycolytic process phosphate-containing compound metabolic process pyridine-containing compound metabolic process small molecule metabolic process purine ribonucleotide catabolic process phosphorus metabolic process pyridine nucleotide metabolic process nucleoside phosphate metabolic process organonitrogen compound catabolic process nicotinamide nucleotide metabolic process pyruvate metabolic process cellular metabolic process purine nucleoside diphosphate metabolic process primary metabolic process purine-containing compound catabolic process nucleotide metabolic process nucleobase-containing compound catabolic process organic cyclic compound metabolic process nucleoside diphosphate metabolic process purine nucleoside diphosphate catabolic process nucleoside diphosphate catabolic process metabolic process nucleoside triphosphate metabolic process monocarboxylic acid metabolic process purine ribonucleotide metabolic process pyridine-containing compound catabolic process ribose phosphate metabolic process catabolic process ATP metabolic process purine nucleotide metabolic process organic substance metabolic process ribonucleotide metabolic process nucleobase-containing small molecule metabolic process purine ribonucleoside triphosphate metabolic process ribonucleoside diphosphate metabolic process ribonucleoside diphosphate catabolic process nucleotide catabolic process ribonucleoside triphosphate metabolic process purine nucleoside triphosphate metabolic process purine nucleotide catabolic process carbohydrate metabolic process carbohydrate derivative catabolic process organonitrogen compound metabolic process ADP catabolic process carboxylic acid metabolic process generation of precursor metabolites and energy organic cyclic compound catabolic process purine-containing compound metabolic process ADP metabolic process organophosphate metabolic process purine ribonucleoside diphosphate metabolic process cellular process organic substance catabolic process purine ribonucleoside diphosphate catabolic process	intracellular anatomical structure cytoplasm cellular anatomical entity

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A, C, E, G	IPR017596	Pyruvate dehydrogenase E1 component subunit alpha/BCKADH E1-alpha	Family
A, C, E, G	IPR029061	Thiamin diphosphate-binding fold	Homologous Superfamily
A, C, E, G	IPR001017	Dehydrogenase, E1 component	Domain
B, D, F, H	IPR005475	Transketolase-like, pyrimidine-binding domain	Domain
B, D, F, H	IPR029061	Thiamin diphosphate-binding fold	Homologous Superfamily
B, D, F, H	IPR009014	Transketolase C-terminal/Pyruvate-ferredoxin oxidoreductase domain II	Homologous Superfamily
B, D, F, H	IPR033248	Transketolase, C-terminal domain	Domain
I, J	IPR001078	2-oxoacid dehydrogenase acyltransferase, catalytic domain	Domain
I, J	IPR023213	Chloramphenicol acetyltransferase-like domain superfamily	Homologous Superfamily
I, J	IPR036625	E3-binding domain superfamily	Homologous Superfamily
I, J	IPR004167	Peripheral subunit-binding domain	Domain
I, J	IPR011053	Single hybrid motif	Homologous Superfamily
I, J	IPR003016	2-oxo acid dehydrogenase, lipoyl-binding site	Binding Site
I, J	IPR000089	Biotin/lipoyl attachment	Domain

RCSB PDB Core Operations are funded by the National Science Foundation (DBI-1832184), 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 R01GM133198.