7L1U | pdb_00007l1u

Orexin Receptor 2 (OX2R) in Complex with G Protein and Natural Peptide-Agonist Orexin B (OxB)

External Resource: Annotation

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
Membrane Protein Annotation: OPM
Membrane Protein Annotation: PDBTM
Membrane Protein Annotation: MemProtMD
Membrane Protein Annotation: mpstruc
Protein Modification Annotation

Domain Annotation: SCOP2 Classification SCOP2 Database Homepage

Chains	Type	Family Name	Domain Identifier	Family Identifier	Provenance Source (Version)
C	SCOP2B Superfamily	Transducin (heterotrimeric G protein), gamma chain	8070798	3001771	SCOP2B (2022-06-29)
E [auth R]	SCOP2B Superfamily	G protein-coupled receptor-like	8091148	3000473	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	Ras	e7l1uA1	A: a/b three-layered sandwiches	X: P-loop domains-like	H: P-loop domains-related	T: P-loop containing nucleoside triphosphate hydrolases	F: Ras	ECOD (1.6)
B	ANAPC4_WD40_3	e7l1uB1	A: beta duplicates or obligate multimers	X: beta-propeller-like	H: beta-propeller	T: 7-bladed	F: ANAPC4_WD40_3	ECOD (1.6)
C	G-gamma	e7l1uC1	A: extended segments	X: Transducin (heterotrimeric G protein), gamma chain (From Topology)	H: Transducin (heterotrimeric G protein), gamma chain (From Topology)	T: Transducin (heterotrimeric G protein), gamma chain	F: G-gamma	ECOD (1.6)
D [auth H]	V-set	e7l1uH1	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: V-set	ECOD (1.6)
D [auth H]	V-set_12	e7l1uH2	A: beta sandwiches	X: Immunoglobulin-like beta-sandwich	H: Immunoglobulin-related	T: Immunoglobulin/Fibronectin type III/E set domains/PapD-like	F: V-set_12	ECOD (1.6)
E [auth R]	7tm_1_1	e7l1uR1	A: alpha bundles	X: Family A G protein-coupled receptor-like (From Topology)	H: Family A G protein-coupled receptor-like (From Topology)	T: Family A G protein-coupled receptor-like	F: 7tm_1_1	ECOD (1.6)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
A	3.40.50.300	Alpha Beta	3-Layer(aba) Sandwich	Rossmann fold	P-loop containing nucleotide triphosphate hydrolases	CATH (utative)
B	2.130.10.10	Mainly Beta	7 Propeller	Methylamine Dehydrogenase	Chain H	CATH (utative)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
B	PF00400	WD domain, G-beta repeat (WD40)	WD domain, G-beta repeat	-	Repeat
C	PF00631	GGL domain (G-gamma)	GGL domain	G-protein gamma like domains (GGL) are found in the gamma subunit of the heterotrimeric G protein complex and in regulators of G protein signaling (RGS) proteins [1]. It is also found fused to an inactive Galpha in the Dictyostelium protein gbqA [2] ...	G-protein gamma like domains (GGL) are found in the gamma subunit of the heterotrimeric G protein complex and in regulators of G protein signaling (RGS) proteins [1]. It is also found fused to an inactive Galpha in the Dictyostelium protein gbqA [2]. G-gamma likely shares a common origin with the helical N-terminal unit of G-beta [2]. All organisms that posses a G-beta possess a G-gamma [2].	Domain
E [auth R]	PF00001	7 transmembrane receptor (rhodopsin family) (7tm_1)	7 transmembrane receptor (rhodopsin family)	This family contains, amongst other G-protein-coupled receptors (GCPRs), members of the opsin family, which have been considered to be typical members of the rhodopsin superfamily. They share several motifs, mainly the seven transmembrane helices, GC ...	This family contains, amongst other G-protein-coupled receptors (GCPRs), members of the opsin family, which have been considered to be typical members of the rhodopsin superfamily. They share several motifs, mainly the seven transmembrane helices, GCPRs of the rhodopsin superfamily. All opsins bind a chromophore, such as 11-cis-retinal. The function of most opsins other than the photoisomerases is split into two steps: light absorption and G-protein activation. Photoisomerases, on the other hand, are not coupled to G-proteins - they are thought to generate and supply the chromophore that is used by visual opsins [1].	Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A	Engineered Guanine nucleotide-binding protein subunit alpha	-	-	-
B	Guanine nucleotide-binding protein G(I)/G(S)/G(T) subunit beta-1	protein binding binding enzyme binding GTPase binding protein-containing complex binding pyrophosphatase activity GTPase activity ribonucleoside triphosphate phosphatase activity hydrolase activity, acting on acid anhydrides, in phosphorus-containing anhydrides hydrolase activity hydrolase activity, acting on acid anhydrides catalytic activity signaling receptor complex adaptor activity protein-macromolecule adaptor activity protein binding binding enzyme binding GTPase binding protein-containing complex binding pyrophosphatase activity GTPase activity ribonucleoside triphosphate phosphatase activity hydrolase activity, acting on acid anhydrides, in phosphorus-containing anhydrides hydrolase activity hydrolase activity, acting on acid anhydrides catalytic activity signaling receptor complex adaptor activity protein-macromolecule adaptor activity molecular adaptor activity signaling adaptor activity	multicellular organismal process system process sensory perception of chemical stimulus sensory perception nervous system process sensory perception of taste developmental process sensory organ development eye development animal organ development retina development in camera-type eye visual system development multicellular organism development camera-type eye development multicellular organismal process system process sensory perception of chemical stimulus sensory perception nervous system process sensory perception of taste developmental process sensory organ development eye development animal organ development retina development in camera-type eye visual system development multicellular organism development camera-type eye development anatomical structure development sensory system development system development cell population proliferation cellular process cellular response to stimulus regulation of biological process regulation of cellular process response to stimulus signaling biological regulation signal transduction cell communication response to ketone response to prostaglandin response to lipid response to endogenous stimulus response to alcohol cellular response to prostaglandin stimulus response to oxygen-containing compound cellular response to oxygen-containing compound cellular response to endogenous stimulus cellular response to prostaglandin E stimulus cellular response to chemical stimulus cellular response to alcohol response to hormone response to chemical cellular response to lipid response to prostaglandin E cellular response to ketone cellular response to hormone stimulus small GTPase-mediated signal transduction Ras protein signal transduction intracellular signal transduction intracellular signaling cassette phospholipase C-activating G protein-coupled receptor signaling pathway G protein-coupled receptor signaling pathway cellular response to nitrogen compound response to dopamine cellular response to dopamine response to monoamine response to catecholamine adenylate cyclase-activating dopamine receptor signaling pathway cellular response to catecholamine stimulus G protein-coupled dopamine receptor signaling pathway response to nitrogen compound adenylate cyclase-activating G protein-coupled receptor signaling pathway cellular response to monoamine stimulus adenylate cyclase-modulating G protein-coupled receptor signaling pathway synaptic signaling cellular response to acetylcholine cell-cell signaling acetylcholine receptor signaling pathway postsynaptic signal transduction G protein-coupled acetylcholine receptor signaling pathway response to acetylcholine	cellular anatomical structure membrane protein-containing complex extrinsic component of plasma membrane catalytic complex plasma membrane protein complex cytoplasmic side of membrane plasma membrane membrane protein complex heterotrimeric G-protein complex side of membrane cell periphery cytoplasmic side of plasma membrane GTPase complex cellular anatomical structure membrane protein-containing complex extrinsic component of plasma membrane catalytic complex plasma membrane protein complex cytoplasmic side of membrane plasma membrane membrane protein complex heterotrimeric G-protein complex side of membrane cell periphery cytoplasmic side of plasma membrane GTPase complex extrinsic component of membrane extrinsic component of cytoplasmic side of plasma membrane extracellular exosome membrane-bounded organelle extracellular vesicle extracellular organelle extracellular region organelle extracellular space vesicle extracellular membrane-bounded organelle non-motile cilium 9+0 non-motile cilium cilium neuron projection photoreceptor disc membrane photoreceptor outer segment plasma membrane bounded cell projection cell projection photoreceptor cell cilium organelle membrane intracellular anatomical structure cytoplasm cytosol vacuolar membrane lytic vacuole vacuole intracellular membrane-bounded organelle intracellular organelle lytic vacuole membrane bounding membrane of organelle lysosomal membrane lysosome synapse cell junction
C	Guanine nucleotide-binding protein G(I)/G(S)/G(O) subunit gamma-2	protein binding binding G-protein beta-subunit binding	fibroblast proliferation cell population proliferation cellular process cellular response to nitrogen compound cellular response to stimulus response to dopamine regulation of cellular process response to stimulus signaling cellular response to dopamine response to monoamine cell communication response to catecholamine adenylate cyclase-activating dopamine receptor signaling pathway fibroblast proliferation cell population proliferation cellular process cellular response to nitrogen compound cellular response to stimulus response to dopamine regulation of cellular process response to stimulus signaling cellular response to dopamine response to monoamine cell communication response to catecholamine adenylate cyclase-activating dopamine receptor signaling pathway cellular response to catecholamine stimulus signal transduction regulation of biological process G protein-coupled dopamine receptor signaling pathway biological regulation response to oxygen-containing compound response to nitrogen compound adenylate cyclase-activating G protein-coupled receptor signaling pathway cellular response to oxygen-containing compound cellular response to chemical stimulus cellular response to monoamine stimulus response to chemical adenylate cyclase-modulating G protein-coupled receptor signaling pathway G protein-coupled receptor signaling pathway response to ketone response to prostaglandin response to lipid response to endogenous stimulus response to alcohol cellular response to prostaglandin stimulus cellular response to endogenous stimulus cellular response to prostaglandin E stimulus cellular response to alcohol response to hormone cellular response to lipid response to prostaglandin E cellular response to ketone cellular response to hormone stimulus	cellular anatomical structure membrane protein-containing complex extrinsic component of plasma membrane catalytic complex plasma membrane protein complex cytoplasmic side of membrane plasma membrane membrane protein complex heterotrimeric G-protein complex side of membrane cell periphery cytoplasmic side of plasma membrane GTPase complex cellular anatomical structure membrane protein-containing complex extrinsic component of plasma membrane catalytic complex plasma membrane protein complex cytoplasmic side of membrane plasma membrane membrane protein complex heterotrimeric G-protein complex side of membrane cell periphery cytoplasmic side of plasma membrane GTPase complex extrinsic component of membrane extrinsic component of cytoplasmic side of plasma membrane extracellular exosome membrane-bounded organelle extracellular vesicle extracellular organelle extracellular region organelle extracellular space vesicle extracellular membrane-bounded organelle synapse cell junction
D [auth H]	single-chain antibody Fv fragment (svFv16)	-	-	-
E [auth R]	Hypocretin receptor type 2	peptide receptor activity molecular transducer activity orexin receptor activity G protein-coupled receptor activity G protein-coupled peptide receptor activity signaling receptor activity transmembrane signaling receptor activity amide binding binding peptide hormone binding hormone binding neuropeptide receptor activity	cellular response to stimulus regulation of biological process regulation of cellular process response to stimulus signaling biological regulation cell communication G protein-coupled receptor signaling pathway cellular process signal transduction neuropeptide signaling pathway locomotion phospholipase C-activating G protein-coupled receptor signaling pathway rhythmic process cellular response to stimulus regulation of biological process regulation of cellular process response to stimulus signaling biological regulation cell communication G protein-coupled receptor signaling pathway cellular process signal transduction neuropeptide signaling pathway locomotion phospholipase C-activating G protein-coupled receptor signaling pathway rhythmic process circadian sleep/wake cycle multicellular organismal process rhythmic behavior circadian rhythm regulation of circadian sleep/wake cycle regulation of circadian sleep/wake cycle, wakefulness regulation of circadian rhythm behavior regulation of behavior circadian behavior circadian sleep/wake cycle, wakefulness regulation of multicellular organismal process circadian sleep/wake cycle process trans-synaptic signaling synaptic signaling anterograde trans-synaptic signaling cell-cell signaling chemical synaptic transmission cellular response to endogenous stimulus cellular response to chemical stimulus response to hormone response to endogenous stimulus response to chemical cellular response to hormone stimulus inorganic ion homeostasis intracellular calcium ion homeostasis homeostatic process calcium ion homeostasis regulation of cytosolic calcium ion concentration cellular homeostasis chemical homeostasis intracellular monoatomic cation homeostasis monoatomic ion homeostasis intracellular chemical homeostasis monoatomic cation homeostasis intracellular monoatomic ion homeostasis feeding behavior	cellular anatomical structure synapse cell junction cell periphery plasma membrane membrane
F [auth L]	Orexin	molecular transducer activity binding molecular function activator activity signaling receptor binding signaling receptor activity neuropeptide activity signaling receptor activator activity hormone activity protein binding molecular function regulator activity neuropeptide hormone activity signaling receptor regulator activity receptor ligand activity type 2 orexin receptor binding molecular transducer activity binding molecular function activator activity signaling receptor binding signaling receptor activity neuropeptide activity signaling receptor activator activity hormone activity protein binding molecular function regulator activity neuropeptide hormone activity signaling receptor regulator activity receptor ligand activity type 2 orexin receptor binding orexin receptor binding G protein-coupled receptor binding neuropeptide receptor binding type 1 orexin receptor binding	cellular response to stimulus regulation of biological process regulation of cellular process response to stimulus signaling biological regulation cell communication G protein-coupled receptor signaling pathway cellular process signal transduction neuropeptide signaling pathway negative regulation of potassium ion transport regulation of localization regulation of potassium ion transport cellular response to stimulus regulation of biological process regulation of cellular process response to stimulus signaling biological regulation cell communication G protein-coupled receptor signaling pathway cellular process signal transduction neuropeptide signaling pathway negative regulation of potassium ion transport regulation of localization regulation of potassium ion transport transport regulation of transport negative regulation of monoatomic ion transport regulation of monoatomic ion transport negative regulation of biological process negative regulation of transport establishment of localization metal ion transport localization monoatomic ion transport potassium ion transport monoatomic cation transport regulation of metal ion transport positive regulation of cytosolic calcium ion concentration regulation of biological quality positive regulation of cell communication multicellular organismal process system process nervous system process regulation of system process positive regulation of biological process positive regulation of transmission of nerve impulse transmission of nerve impulse regulation of nervous system process regulation of transmission of nerve impulse positive regulation of nervous system process positive regulation of multicellular organismal process regulation of cell communication regulation of multicellular organismal process positive regulation of cellular process negative regulation of nervous system process negative regulation of transmission of nerve impulse negative regulation of cell communication negative regulation of cellular process negative regulation of multicellular organismal process behavior eating behavior feeding behavior cellular localization modulation of chemical synaptic transmission synaptic signaling regulation of secretion by cell secretion by cell signal release establishment of localization in cell trans-synaptic signaling regulation of signaling neurotransmitter secretion secretion regulation of neurotransmitter transport export from cell cell-cell signaling neurotransmitter transport regulation of secretion chemical synaptic transmission signal release from synapse regulation of trans-synaptic signaling regulation of neurotransmitter secretion anterograde trans-synaptic signaling sleep regulation of postsynaptic membrane potential chemical synaptic transmission, postsynaptic cell surface receptor signaling pathway excitatory postsynaptic potential regulation of membrane potential homeostatic process adaptive thermogenesis positive regulation of metabolic process multicellular organismal-level homeostasis regulation of cold-induced thermogenesis cold-induced thermogenesis temperature homeostasis positive regulation of cold-induced thermogenesis metabolic process regulation of metabolic process phospholipase C-activating G protein-coupled receptor signaling pathway regulation of calcium ion transport positive regulation of calcium ion transport calcium ion transport positive regulation of transport positive regulation of monoatomic ion transport regulation of primary metabolic process nucleobase-containing compound metabolic process negative regulation of nucleobase-containing compound metabolic process regulation of nucleobase-containing compound metabolic process negative regulation of macromolecule metabolic process negative regulation of DNA replication negative regulation of metabolic process primary metabolic process regulation of macromolecule metabolic process DNA metabolic process nucleic acid metabolic process DNA replication negative regulation of DNA metabolic process macromolecule metabolic process regulation of DNA metabolic process regulation of DNA replication response to nutrient levels response to stress response to starvation response to alcohol response to chemical response to oxygen-containing compound	membrane-bounded organelle intracellular anatomical structure intracellular vesicle membrane-enclosed lumen cytoplasmic vesicle lumen endomembrane system intracellular organelle lumen intracellular organelle cellular anatomical structure cytoplasmic vesicle neuronal dense core vesicle lumen vesicle neuronal dense core vesicle vesicle lumen membrane-bounded organelle intracellular anatomical structure intracellular vesicle membrane-enclosed lumen cytoplasmic vesicle lumen endomembrane system intracellular organelle lumen intracellular organelle cellular anatomical structure cytoplasmic vesicle neuronal dense core vesicle lumen vesicle neuronal dense core vesicle vesicle lumen dense core granule intracellular membrane-bounded organelle secretory granule lumen organelle lumen organelle secretory granule dense core granule lumen secretory vesicle cytoplasm rough endoplasmic reticulum endoplasmic reticulum extracellular region perinuclear region of cytoplasm postsynapse synapse cell junction transport vesicle presynapse synaptic vesicle exocytic vesicle

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
B	IPR019775	WD40 repeat, conserved site	Conserved Site
B	IPR015943	WD40/YVTN repeat-like-containing domain superfamily	Homologous Superfamily
B	IPR016346	Guanine nucleotide-binding protein, beta subunit	Family
B	IPR036322	WD40-repeat-containing domain superfamily	Homologous Superfamily
B	IPR001632	G-protein, beta subunit	Domain
B	IPR001680	WD40 repeat	Repeat
B	IPR020472	G-protein beta WD-40 repeat	Repeat
C	IPR015898	G-protein gamma-like domain	Domain
C	IPR001770	G-protein, gamma subunit	Family
C	IPR036284	G-protein gamma-like domain superfamily	Homologous Superfamily
E [auth R]	IPR000276	G protein-coupled receptor, rhodopsin-like	Family
E [auth R]	IPR004060	Orexin receptor 2	Family
E [auth R]	IPR017452	GPCR, rhodopsin-like, 7TM	Domain
E [auth R]	IPR000204	Orexin receptor family	Family
F [auth L]	IPR001704	Prepro-orexin	Family

Pharos: Disease Associations Pharos Homepage Annotation

Chains	Drug Target	Associated Disease
B	Pharos: P62873	intellectual disability, autosomal dominant 42 melancholia intellectual disability endogenous depression medulloblastoma myopathy ovarian cancer Precursor Cell Lymphoblastic Leukemia Lymphoma anxiety disorder Sjogren syndrome chronic kidney disease juvenile dermatomyositis lung adenocarcinoma neurotic disorder pancreatic ductal adenocarcinoma intellectual disability, autosomal dominant 42 melancholia intellectual disability endogenous depression medulloblastoma myopathy ovarian cancer Precursor Cell Lymphoblastic Leukemia Lymphoma anxiety disorder Sjogren syndrome chronic kidney disease juvenile dermatomyositis lung adenocarcinoma neurotic disorder pancreatic ductal adenocarcinoma subependymal giant cell astrocytoma breast cancer Duchenne muscular dystrophy leukemia, acute lymphocytic, susceptibility to, 1 malignant pancreatic neoplasm myelodysplastic syndrome osteosarcoma plasma cell myeloma rheumatoid arthritis swine influenza childhood acute lymphoblastic leukemia depressive disorder
C	Pharos: P59768	pancreatic intraductal papillary-mucinous neoplasm pilocytic astrocytoma sarcoidosis ulcerative colitis adrenal cortex carcinoma breast carcinoma Duchenne muscular dystrophy glioblastoma large cell medulloblastoma medulloblastoma ovarian cancer pancreatic intraductal papillary-mucinous neoplasm with low grade dysplasia pituitary cancer Sjogren syndrome X-linked mixed deafness with perilymphatic gusher pancreatic intraductal papillary-mucinous neoplasm pilocytic astrocytoma sarcoidosis ulcerative colitis adrenal cortex carcinoma breast carcinoma Duchenne muscular dystrophy glioblastoma large cell medulloblastoma medulloblastoma ovarian cancer pancreatic intraductal papillary-mucinous neoplasm with low grade dysplasia pituitary cancer Sjogren syndrome X-linked mixed deafness with perilymphatic gusher astrocytic tumor Crohn disease ductal breast carcinoma in situ interstitial cystitis lung carcinoma non-small cell lung carcinoma pancreatic intraductal papillary-mucinous carcinoma Pick disease primitive neuroectodermal tumor thoracic aortic aneurysm atypical teratoid rhabdoid tumor cystic fibrosis Emery-Dreifuss muscular dystrophy invasive ductal breast carcinoma malignant ependymoma osteosarcoma
E [auth R]	Pharos: O43614	narcolepsy insomnia narcolepsy-cataplexy syndrome
F [auth L]	Pharos: O43612	narcolepsy 1 narcolepsy-cataplexy syndrome cocaine abuse Pain cocaine dependence substance withdrawal syndrome narcolepsy obesity disorder heart disease neurodegenerative disease sleep-wake disorder cannabis dependence vitiligo hypothyroidism narcolepsy without cataplexy narcolepsy 1 narcolepsy-cataplexy syndrome cocaine abuse Pain cocaine dependence substance withdrawal syndrome narcolepsy obesity disorder heart disease neurodegenerative disease sleep-wake disorder cannabis dependence vitiligo hypothyroidism narcolepsy without cataplexy depressive disorder Hashimoto thyroiditis Kleine-Levin syndrome

Membrane Protein Annotation: OPM OPM Database Homepage

Chains	External Link	Type	Class	Superfamily	Family
C, E [auth R], F [auth L]	OPM	Transmembrane	Alpha-helical polytopic	Rhodopsin-like receptors and pumps	G-protein coupled receptors, family A

Membrane Protein Annotation: PDBTM PDBTM Database Homepage

Chains	External Link	Comment
C, E [auth R], F [auth L]	PDBTM	Annotated as membrane protein by PDBTM

Membrane Protein Annotation: MemProtMD MemProtMD Database Homepage

Chains	External Link	Comment
C, E [auth R], F [auth L]	MemProtMD	Annotated as membrane protein by MemProtMD

Membrane Protein Annotation: mpstruc mpstruc Database Homepage

Chains	Resource Link	Group	Subgroup	Protein
C, E [auth R], F [auth L]	mpstruc	TRANSMEMBRANE PROTEINS: ALPHA-HELICAL	G Protein-Coupled Receptors: Class A	OX₂ orexin receptor in complex with G protein and natural peptide-agonist Orexin B (OxB)

Protein Modification Annotation

Modified Residue(s)
Chain	Residue(s)	Description
F [auth L]	NH2	RESID: AA0081 , AA0083 , AA0084 , AA0086 , AA0087 , AA0088 , AA0090 , AA0091 , AA0092 , AA0093 , AA0095 , AA0096 , AA0097 , AA0098 , AA0099 , AA0100 PSI-MOD : L-alanine amide MOD:00090 , L-asparagine amide MOD:00092 , L-aspartic acid 1-amide MOD:00093 , L-glutamine amide MOD:00095 , L-glutamic acid 1-amide MOD:00096 , glycine amide MOD:00097 , L-isoleucine amide MOD:00099 , L-leucine amide MOD:00100 , L-lysine amide MOD:00101 , L-methionine amide MOD:00102 , L-proline amide MOD:00104 , L-serine amide MOD:00105 , L-threonine amide MOD:00106 , L-tryptophan amide MOD:00107 , L-tyrosine amide MOD:00108 , L-valine amide MOD:00109

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.