Annotations: 3TDK

Domain Annotation: ECOD Classification ECOD Database Homepage

Chains	Family Name	Domain Identifier	Architecture	Possible Homology	Homology	Topology	Family	Provenance Source (Version)
A	PF00984	e3tdkA2	A: alpha arrays	X: 6-phosphogluconate dehydrogenase C-terminal domain-like (From Topology)	H: 6-phosphogluconate dehydrogenase C-terminal domain-like (From Topology)	T: 6-phosphogluconate dehydrogenase C-terminal domain-like	F: PF00984	ECOD (1.6)
A	PF03721	e3tdkA3	A: a/b three-layered sandwiches	X: Rossmann-like	H: Rossmann-related	T: NAD(P)-binding Rossmann-fold domains	F: PF03721	ECOD (1.6)
A	PF03720	e3tdkA1	A: a/b three-layered sandwiches	X: Rossmann-like	H: Rossmann-related	T: UDPG/MGDP dehydrogenase C-terminal domain	F: PF03720	ECOD (1.6)
B	PF00984	e3tdkB2	A: alpha arrays	X: 6-phosphogluconate dehydrogenase C-terminal domain-like (From Topology)	H: 6-phosphogluconate dehydrogenase C-terminal domain-like (From Topology)	T: 6-phosphogluconate dehydrogenase C-terminal domain-like	F: PF00984	ECOD (1.6)
B	PF03721	e3tdkB3	A: a/b three-layered sandwiches	X: Rossmann-like	H: Rossmann-related	T: NAD(P)-binding Rossmann-fold domains	F: PF03721	ECOD (1.6)
B	PF03720	e3tdkB1	A: a/b three-layered sandwiches	X: Rossmann-like	H: Rossmann-related	T: UDPG/MGDP dehydrogenase C-terminal domain	F: PF03720	ECOD (1.6)
C [auth G]	PF00984	e3tdkG1	A: alpha arrays	X: 6-phosphogluconate dehydrogenase C-terminal domain-like (From Topology)	H: 6-phosphogluconate dehydrogenase C-terminal domain-like (From Topology)	T: 6-phosphogluconate dehydrogenase C-terminal domain-like	F: PF00984	ECOD (1.6)
C [auth G]	PF03721	e3tdkG3	A: a/b three-layered sandwiches	X: Rossmann-like	H: Rossmann-related	T: NAD(P)-binding Rossmann-fold domains	F: PF03721	ECOD (1.6)
C [auth G]	PF03720	e3tdkG2	A: a/b three-layered sandwiches	X: Rossmann-like	H: Rossmann-related	T: UDPG/MGDP dehydrogenase C-terminal domain	F: PF03720	ECOD (1.6)
D [auth H]	PF00984	e3tdkH2	A: alpha arrays	X: 6-phosphogluconate dehydrogenase C-terminal domain-like (From Topology)	H: 6-phosphogluconate dehydrogenase C-terminal domain-like (From Topology)	T: 6-phosphogluconate dehydrogenase C-terminal domain-like	F: PF00984	ECOD (1.6)
D [auth H]	PF03721	e3tdkH1	A: a/b three-layered sandwiches	X: Rossmann-like	H: Rossmann-related	T: NAD(P)-binding Rossmann-fold domains	F: PF03721	ECOD (1.6)
D [auth H]	PF03720	e3tdkH3	A: a/b three-layered sandwiches	X: Rossmann-like	H: Rossmann-related	T: UDPG/MGDP dehydrogenase C-terminal domain	F: PF03720	ECOD (1.6)
F [auth K]	PF00984	e3tdkK3	A: alpha arrays	X: 6-phosphogluconate dehydrogenase C-terminal domain-like (From Topology)	H: 6-phosphogluconate dehydrogenase C-terminal domain-like (From Topology)	T: 6-phosphogluconate dehydrogenase C-terminal domain-like	F: PF00984	ECOD (1.6)
F [auth K]	PF03721	e3tdkK2	A: a/b three-layered sandwiches	X: Rossmann-like	H: Rossmann-related	T: NAD(P)-binding Rossmann-fold domains	F: PF03721	ECOD (1.6)
F [auth K]	PF03720	e3tdkK1	A: a/b three-layered sandwiches	X: Rossmann-like	H: Rossmann-related	T: UDPG/MGDP dehydrogenase C-terminal domain	F: PF03720	ECOD (1.6)
G [auth F]	PF00984	e3tdkF1	A: alpha arrays	X: 6-phosphogluconate dehydrogenase C-terminal domain-like (From Topology)	H: 6-phosphogluconate dehydrogenase C-terminal domain-like (From Topology)	T: 6-phosphogluconate dehydrogenase C-terminal domain-like	F: PF00984	ECOD (1.6)
G [auth F]	PF03721	e3tdkF3	A: a/b three-layered sandwiches	X: Rossmann-like	H: Rossmann-related	T: NAD(P)-binding Rossmann-fold domains	F: PF03721	ECOD (1.6)
G [auth F]	PF03720	e3tdkF2	A: a/b three-layered sandwiches	X: Rossmann-like	H: Rossmann-related	T: UDPG/MGDP dehydrogenase C-terminal domain	F: PF03720	ECOD (1.6)
H [auth E]	PF00984	e3tdkE2	A: alpha arrays	X: 6-phosphogluconate dehydrogenase C-terminal domain-like (From Topology)	H: 6-phosphogluconate dehydrogenase C-terminal domain-like (From Topology)	T: 6-phosphogluconate dehydrogenase C-terminal domain-like	F: PF00984	ECOD (1.6)
H [auth E]	PF03721	e3tdkE1	A: a/b three-layered sandwiches	X: Rossmann-like	H: Rossmann-related	T: NAD(P)-binding Rossmann-fold domains	F: PF03721	ECOD (1.6)
H [auth E]	PF03720	e3tdkE3	A: a/b three-layered sandwiches	X: Rossmann-like	H: Rossmann-related	T: UDPG/MGDP dehydrogenase C-terminal domain	F: PF03720	ECOD (1.6)
I [auth D]	PF00984	e3tdkD3	A: alpha arrays	X: 6-phosphogluconate dehydrogenase C-terminal domain-like (From Topology)	H: 6-phosphogluconate dehydrogenase C-terminal domain-like (From Topology)	T: 6-phosphogluconate dehydrogenase C-terminal domain-like	F: PF00984	ECOD (1.6)
I [auth D]	PF03721	e3tdkD2	A: a/b three-layered sandwiches	X: Rossmann-like	H: Rossmann-related	T: NAD(P)-binding Rossmann-fold domains	F: PF03721	ECOD (1.6)
I [auth D]	PF03720	e3tdkD1	A: a/b three-layered sandwiches	X: Rossmann-like	H: Rossmann-related	T: UDPG/MGDP dehydrogenase C-terminal domain	F: PF03720	ECOD (1.6)
J [auth C]	PF00984	e3tdkC3	A: alpha arrays	X: 6-phosphogluconate dehydrogenase C-terminal domain-like (From Topology)	H: 6-phosphogluconate dehydrogenase C-terminal domain-like (From Topology)	T: 6-phosphogluconate dehydrogenase C-terminal domain-like	F: PF00984	ECOD (1.6)
J [auth C]	PF03721	e3tdkC2	A: a/b three-layered sandwiches	X: Rossmann-like	H: Rossmann-related	T: NAD(P)-binding Rossmann-fold domains	F: PF03721	ECOD (1.6)
J [auth C]	PF03720	e3tdkC1	A: a/b three-layered sandwiches	X: Rossmann-like	H: Rossmann-related	T: UDPG/MGDP dehydrogenase C-terminal domain	F: PF03720	ECOD (1.6)
K [auth J]	PF00984	e3tdkJ1	A: alpha arrays	X: 6-phosphogluconate dehydrogenase C-terminal domain-like (From Topology)	H: 6-phosphogluconate dehydrogenase C-terminal domain-like (From Topology)	T: 6-phosphogluconate dehydrogenase C-terminal domain-like	F: PF00984	ECOD (1.6)
K [auth J]	PF03721	e3tdkJ3	A: a/b three-layered sandwiches	X: Rossmann-like	H: Rossmann-related	T: NAD(P)-binding Rossmann-fold domains	F: PF03721	ECOD (1.6)
K [auth J]	PF03720	e3tdkJ2	A: a/b three-layered sandwiches	X: Rossmann-like	H: Rossmann-related	T: UDPG/MGDP dehydrogenase C-terminal domain	F: PF03720	ECOD (1.6)
L [auth I]	PF00984	e3tdkI3	A: alpha arrays	X: 6-phosphogluconate dehydrogenase C-terminal domain-like (From Topology)	H: 6-phosphogluconate dehydrogenase C-terminal domain-like (From Topology)	T: 6-phosphogluconate dehydrogenase C-terminal domain-like	F: PF00984	ECOD (1.6)
L [auth I]	PF03721	e3tdkI1	A: a/b three-layered sandwiches	X: Rossmann-like	H: Rossmann-related	T: NAD(P)-binding Rossmann-fold domains	F: PF03721	ECOD (1.6)
L [auth I]	PF03720	e3tdkI2	A: a/b three-layered sandwiches	X: Rossmann-like	H: Rossmann-related	T: UDPG/MGDP dehydrogenase C-terminal domain	F: PF03720	ECOD (1.6)
E [auth L]	PF00984	e3tdkL3	A: alpha arrays	X: 6-phosphogluconate dehydrogenase C-terminal domain-like (From Topology)	H: 6-phosphogluconate dehydrogenase C-terminal domain-like (From Topology)	T: 6-phosphogluconate dehydrogenase C-terminal domain-like	F: PF00984	ECOD (1.6)
E [auth L]	PF03721	e3tdkL2	A: a/b three-layered sandwiches	X: Rossmann-like	H: Rossmann-related	T: NAD(P)-binding Rossmann-fold domains	F: PF03721	ECOD (1.6)
E [auth L]	PF03720	e3tdkL1	A: a/b three-layered sandwiches	X: Rossmann-like	H: Rossmann-related	T: UDPG/MGDP dehydrogenase C-terminal domain	F: PF03720	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	1.20.5.100	Mainly Alpha	Up-down Bundle	Single alpha-helices involved in coiled-coils or other helix-helix interfaces	Cytochrome c1, transmembrane anchor, C-terminal	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	1.20.5.100	Mainly Alpha	Up-down Bundle	Single alpha-helices involved in coiled-coils or other helix-helix interfaces	Cytochrome c1, transmembrane anchor, C-terminal	CATH (4.3.0)
C [auth G]	3.40.50.720	Alpha Beta	3-Layer(aba) Sandwich	Rossmann fold	NAD(P)-binding Rossmann-like Domain	CATH (4.3.0)
C [auth G]	1.20.5.100	Mainly Alpha	Up-down Bundle	Single alpha-helices involved in coiled-coils or other helix-helix interfaces	Cytochrome c1, transmembrane anchor, C-terminal	CATH (4.3.0)
D [auth H]	3.40.50.720	Alpha Beta	3-Layer(aba) Sandwich	Rossmann fold	NAD(P)-binding Rossmann-like Domain	CATH (4.3.0)
D [auth H]	1.20.5.100	Mainly Alpha	Up-down Bundle	Single alpha-helices involved in coiled-coils or other helix-helix interfaces	Cytochrome c1, transmembrane anchor, C-terminal	CATH (4.3.0)
F [auth K]	3.40.50.720	Alpha Beta	3-Layer(aba) Sandwich	Rossmann fold	NAD(P)-binding Rossmann-like Domain	CATH (4.3.0)
F [auth K]	1.20.5.100	Mainly Alpha	Up-down Bundle	Single alpha-helices involved in coiled-coils or other helix-helix interfaces	Cytochrome c1, transmembrane anchor, C-terminal	CATH (4.3.0)
G [auth F]	3.40.50.720	Alpha Beta	3-Layer(aba) Sandwich	Rossmann fold	NAD(P)-binding Rossmann-like Domain	CATH (4.3.0)
G [auth F]	1.20.5.100	Mainly Alpha	Up-down Bundle	Single alpha-helices involved in coiled-coils or other helix-helix interfaces	Cytochrome c1, transmembrane anchor, C-terminal	CATH (4.3.0)
H [auth E]	3.40.50.720	Alpha Beta	3-Layer(aba) Sandwich	Rossmann fold	NAD(P)-binding Rossmann-like Domain	CATH (4.3.0)
H [auth E]	1.20.5.100	Mainly Alpha	Up-down Bundle	Single alpha-helices involved in coiled-coils or other helix-helix interfaces	Cytochrome c1, transmembrane anchor, C-terminal	CATH (4.3.0)
I [auth D]	3.40.50.720	Alpha Beta	3-Layer(aba) Sandwich	Rossmann fold	NAD(P)-binding Rossmann-like Domain	CATH (4.3.0)
I [auth D]	1.20.5.100	Mainly Alpha	Up-down Bundle	Single alpha-helices involved in coiled-coils or other helix-helix interfaces	Cytochrome c1, transmembrane anchor, C-terminal	CATH (4.3.0)
J [auth C]	3.40.50.720	Alpha Beta	3-Layer(aba) Sandwich	Rossmann fold	NAD(P)-binding Rossmann-like Domain	CATH (4.3.0)
J [auth C]	1.20.5.100	Mainly Alpha	Up-down Bundle	Single alpha-helices involved in coiled-coils or other helix-helix interfaces	Cytochrome c1, transmembrane anchor, C-terminal	CATH (4.3.0)
K [auth J]	3.40.50.720	Alpha Beta	3-Layer(aba) Sandwich	Rossmann fold	NAD(P)-binding Rossmann-like Domain	CATH (4.3.0)
K [auth J]	1.20.5.100	Mainly Alpha	Up-down Bundle	Single alpha-helices involved in coiled-coils or other helix-helix interfaces	Cytochrome c1, transmembrane anchor, C-terminal	CATH (4.3.0)
L [auth I]	3.40.50.720	Alpha Beta	3-Layer(aba) Sandwich	Rossmann fold	NAD(P)-binding Rossmann-like Domain	CATH (4.3.0)
L [auth I]	1.20.5.100	Mainly Alpha	Up-down Bundle	Single alpha-helices involved in coiled-coils or other helix-helix interfaces	Cytochrome c1, transmembrane anchor, C-terminal	CATH (4.3.0)
E [auth L]	3.40.50.720	Alpha Beta	3-Layer(aba) Sandwich	Rossmann fold	NAD(P)-binding Rossmann-like Domain	CATH (4.3.0)
E [auth L]	1.20.5.100	Mainly Alpha	Up-down Bundle	Single alpha-helices involved in coiled-coils or other helix-helix interfaces	Cytochrome c1, transmembrane anchor, C-terminal	CATH (4.3.0)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
A, B, C [auth G], D [auth H], E [auth L], A, B, C [auth G], D [auth H], E [auth L], F [auth K], G [auth F], H [auth E], I [auth D], J [auth C], K [auth J], L [auth I]	PF03720	UDP-glucose/GDP-mannose dehydrogenase family, UDP binding domain (UDPG_MGDP_dh_C)	UDP-glucose/GDP-mannose dehydrogenase family, UDP binding domain	The UDP-glucose/GDP-mannose dehydrogenaseses are a small group of enzymes which possesses the ability to catalyse the NAD-dependent 2-fold oxidation of an alcohol to an acid without the release of an aldehyde intermediate [2].	Domain
A, B, C [auth G], D [auth H], E [auth L], A, B, C [auth G], D [auth H], E [auth L], F [auth K], G [auth F], H [auth E], I [auth D], J [auth C], K [auth J], L [auth I]	PF00984	UDP-glucose/GDP-mannose dehydrogenase family, central domain (UDPG_MGDP_dh)	UDP-glucose/GDP-mannose dehydrogenase family, central domain	The UDP-glucose/GDP-mannose dehydrogenaseses are a small group of enzymes which possesses the ability to catalyse the NAD-dependent 2-fold oxidation of an alcohol to an acid without the release of an aldehyde intermediate [2].	Domain
A, B, C [auth G], D [auth H], E [auth L], A, B, C [auth G], D [auth H], E [auth L], F [auth K], G [auth F], H [auth E], I [auth D], J [auth C], K [auth J], L [auth I]	PF03721	UDP-glucose/GDP-mannose dehydrogenase family, NAD binding domain (UDPG_MGDP_dh_N)	UDP-glucose/GDP-mannose dehydrogenase family, NAD binding domain	The UDP-glucose/GDP-mannose dehydrogenaseses are a small group of enzymes which possesses the ability to catalyse the NAD-dependent 2-fold oxidation of an alcohol to an acid without the release of an aldehyde intermediate [2].	Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A, B, C [auth G], D [auth H], E [auth L], A, B, C [auth G], D [auth H], E [auth L], F [auth K], G [auth F], H [auth E], I [auth D], J [auth C], K [auth J], L [auth I]	UDP-glucose 6-dehydrogenase	NAD binding binding nucleoside phosphate binding purine nucleotide binding organic cyclic compound binding adenyl nucleotide binding nucleotide binding heterocyclic compound binding small molecule binding oxidoreductase activity oxidoreductase activity, acting on the CH-OH group of donors, NAD or NADP as acceptor oxidoreductase activity, acting on CH-OH group of donors UDP-glucose 6-dehydrogenase activity catalytic activity NAD binding binding nucleoside phosphate binding purine nucleotide binding organic cyclic compound binding adenyl nucleotide binding nucleotide binding heterocyclic compound binding small molecule binding oxidoreductase activity oxidoreductase activity, acting on the CH-OH group of donors, NAD or NADP as acceptor oxidoreductase activity, acting on CH-OH group of donors UDP-glucose 6-dehydrogenase activity catalytic activity identical protein binding protein binding	oxoacid metabolic process UDP-glucuronate metabolic process cellular biosynthetic process carbohydrate derivative metabolic process organic acid biosynthetic process organic acid metabolic process carboxylic acid biosynthetic process UDP-glucuronate biosynthetic process nucleobase-containing compound metabolic process organic substance metabolic process nucleobase-containing small molecule metabolic process organic substance biosynthetic process small molecule metabolic process phosphorus metabolic process oxoacid metabolic process UDP-glucuronate metabolic process cellular biosynthetic process carbohydrate derivative metabolic process organic acid biosynthetic process organic acid metabolic process carboxylic acid biosynthetic process UDP-glucuronate biosynthetic process nucleobase-containing compound metabolic process organic substance metabolic process nucleobase-containing small molecule metabolic process organic substance biosynthetic process small molecule metabolic process phosphorus metabolic process nucleotide-sugar biosynthetic process carbohydrate derivative biosynthetic process small molecule biosynthetic process cellular metabolic process nucleotide-sugar metabolic process carboxylic acid metabolic process primary metabolic process nucleobase-containing compound biosynthetic process organic cyclic compound metabolic process biosynthetic process organic cyclic compound biosynthetic process metabolic process cellular process developmental process multicellular organism development multicellular organismal process anatomical structure morphogenesis gastrulation with mouth forming second embryonic morphogenesis anatomical structure development embryo development gastrulation organonitrogen compound metabolic process glycosaminoglycan metabolic process organonitrogen compound biosynthetic process macromolecule biosynthetic process aminoglycan metabolic process aminoglycan biosynthetic process glycosaminoglycan biosynthetic process macromolecule metabolic process mucopolysaccharide metabolic process proteoglycan biosynthetic process sulfur compound metabolic process protein metabolic process chondroitin sulfate metabolic process glycoprotein biosynthetic process chondroitin sulfate proteoglycan metabolic process glycoprotein metabolic process chondroitin sulfate biosynthetic process sulfur compound biosynthetic process chondroitin sulfate proteoglycan biosynthetic process proteoglycan metabolic process carbohydrate metabolic process cellular component organization cellular component biogenesis protein hexamerization cellular component assembly protein-containing complex organization protein complex oligomerization protein-containing complex assembly cellular component organization or biogenesis heparan sulfate proteoglycan biosynthetic process cellular developmental process cell development nervous system development generation of neurons neurogenesis neuron differentiation cell differentiation neuron development system development	extracellular exosome membrane-bounded organelle extracellular vesicle extracellular organelle extracellular region organelle extracellular space cellular anatomical entity vesicle extracellular membrane-bounded organelle intracellular anatomical structure cytoplasm cytosol nucleus extracellular exosome membrane-bounded organelle extracellular vesicle extracellular organelle extracellular region organelle extracellular space cellular anatomical entity vesicle extracellular membrane-bounded organelle intracellular anatomical structure cytoplasm cytosol nucleus membrane-enclosed lumen intracellular membrane-bounded organelle intracellular organelle lumen intracellular organelle nucleoplasm organelle lumen nuclear lumen

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A, B, C [auth G], D [auth H], E [auth L], A, B, C [auth G], D [auth H], E [auth L], F [auth K], G [auth F], H [auth E], I [auth D], J [auth C], K [auth J], L [auth I]	IPR008927	6-phosphogluconate dehydrogenase-like, C-terminal domain superfamily	Homologous Superfamily
A, B, C [auth G], D [auth H], E [auth L], A, B, C [auth G], D [auth H], E [auth L], F [auth K], G [auth F], H [auth E], I [auth D], J [auth C], K [auth J], L [auth I]	IPR028356	UDP-glucose 6-dehydrogenase, eukaryotic type	Family
A, B, C [auth G], D [auth H], E [auth L], A, B, C [auth G], D [auth H], E [auth L], F [auth K], G [auth F], H [auth E], I [auth D], J [auth C], K [auth J], L [auth I]	IPR036291	NAD(P)-binding domain superfamily	Homologous Superfamily
A, B, C [auth G], D [auth H], E [auth L], A, B, C [auth G], D [auth H], E [auth L], F [auth K], G [auth F], H [auth E], I [auth D], J [auth C], K [auth J], L [auth I]	IPR017476	UDP-glucose/GDP-mannose dehydrogenase	Family
A, B, C [auth G], D [auth H], E [auth L], A, B, C [auth G], D [auth H], E [auth L], F [auth K], G [auth F], H [auth E], I [auth D], J [auth C], K [auth J], L [auth I]	IPR014026	UDP-glucose/GDP-mannose dehydrogenase, dimerisation	Domain
A, B, C [auth G], D [auth H], E [auth L], A, B, C [auth G], D [auth H], E [auth L], F [auth K], G [auth F], H [auth E], I [auth D], J [auth C], K [auth J], L [auth I]	IPR014027	UDP-glucose/GDP-mannose dehydrogenase, C-terminal	Domain
A, B, C [auth G], D [auth H], E [auth L], A, B, C [auth G], D [auth H], E [auth L], F [auth K], G [auth F], H [auth E], I [auth D], J [auth C], K [auth J], L [auth I]	IPR036220	UDP-glucose/GDP-mannose dehydrogenase, C-terminal domain superfamily	Homologous Superfamily
A, B, C [auth G], D [auth H], E [auth L], A, B, C [auth G], D [auth H], E [auth L], F [auth K], G [auth F], H [auth E], I [auth D], J [auth C], K [auth J], L [auth I]	IPR001732	UDP-glucose/GDP-mannose dehydrogenase, N-terminal	Domain

Pharos: Disease Associations Pharos Homepage Annotation

Chains	Drug Target	Associated Disease
A, B, C [auth G], D [auth H], E [auth L], A, B, C [auth G], D [auth H], E [auth L], F [auth K], G [auth F], H [auth E], I [auth D], J [auth C], K [auth J], L [auth I]	Pharos: O60701	liver cancer atypical teratoid rhabdoid tumor glioblastoma malignant glioma pancreatic ductal adenocarcinoma primitive neuroectodermal tumor breast cancer herpes zoster liver neoplasm medulloblastoma peripheral arterial disease sinusitis epilepsy interstitial cystitis malignant colon neoplasm liver cancer atypical teratoid rhabdoid tumor glioblastoma malignant glioma pancreatic ductal adenocarcinoma primitive neuroectodermal tumor breast cancer herpes zoster liver neoplasm medulloblastoma peripheral arterial disease sinusitis epilepsy interstitial cystitis malignant colon neoplasm ovarian cancer pilocytic astrocytoma ulcerative colitis