Annotations: 1Y76

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

Chains	Domain Info	Class	Fold	Superfamily	Family	Domain	Species	Provenance Source (Version)
A	d1y76a1	All alpha proteins	L27 domain	L27 domain	L27 domain	Associated tight junction protein Pals-1	Norway rat (Rattus norvegicus ) [TaxId: 10116 ],	SCOPe (2.08)
C	d1y76c_	All alpha proteins	L27 domain	L27 domain	L27 domain	Associated tight junction protein Pals-1	Norway rat (Rattus norvegicus ) [TaxId: 10116 ],	SCOPe (2.08)
B	d1y76b1	All alpha proteins	L27 domain	L27 domain	L27 domain	Maguk p55 subfamily member 5, Patj	human (Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)
D	d1y76d_	All alpha proteins	L27 domain	L27 domain	L27 domain	Maguk p55 subfamily member 5, Patj	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	SCOP2 Family	L27 domain	8021768	4000688	SCOP2 (2022-06-29)
A	SCOP2 Superfamily	L27 domain	8034148	3001054	SCOP2 (2022-06-29)
B	SCOP2 Family	L27 domain	8021770	4000688	SCOP2 (2022-06-29)
B	SCOP2 Superfamily	L27 domain	8034150	3001054	SCOP2 (2022-06-29)
D	SCOP2B Superfamily	L27 domain	8034150	3001054	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	L27_2	e1y76A1	A: alpha duplicates or obligate multimers	X: L27 domain (From Topology)	H: L27 domain (From Topology)	T: L27 domain	F: L27_2	ECOD (1.6)
C	L27_2	e1y76C1	A: alpha duplicates or obligate multimers	X: L27 domain (From Topology)	H: L27 domain (From Topology)	T: L27 domain	F: L27_2	ECOD (1.6)
B	L27_N	e1y76B1	A: alpha duplicates or obligate multimers	X: L27 domain (From Topology)	H: L27 domain (From Topology)	T: L27 domain	F: L27_N	ECOD (1.6)
D	L27_N	e1y76D1	A: alpha duplicates or obligate multimers	X: L27 domain (From Topology)	H: L27 domain (From Topology)	T: L27 domain	F: L27_N	ECOD (1.6)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
A	1.10.287.650	Mainly Alpha	Orthogonal Bundle	Helix Hairpins	L27 domain	CATH (4.3.0)
C	1.10.287.650	Mainly Alpha	Orthogonal Bundle	Helix Hairpins	L27 domain	CATH (4.3.0)
B	1.10.287.650	Mainly Alpha	Orthogonal Bundle	Helix Hairpins	L27 domain	CATH (4.3.0)
D	1.10.287.650	Mainly Alpha	Orthogonal Bundle	Helix Hairpins	L27 domain	CATH (4.3.0)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
A, C	PF09045	L27_2 (L27_2)	L27_2	The L27_2 domain is a protein-protein interaction domain capable of organising scaffold proteins into supramolecular assemblies by formation of heteromeric L27_2 domain complexes. L27_2 domain-mediated protein assemblies have been shown to play essen ...	The L27_2 domain is a protein-protein interaction domain capable of organising scaffold proteins into supramolecular assemblies by formation of heteromeric L27_2 domain complexes. L27_2 domain-mediated protein assemblies have been shown to play essential roles in cellular processes including asymmetric cell division, establishment and maintenance of cell polarity, and clustering of receptors and ion channels. Members of this family form specific heterotetrameric complexes, in which each domain contains three alpha-helices. The two N-terminal helices of each L27_2 domain pack together to form a tight, four-helix bundle in the heterodimer, whilst the third helix of each L27_2 domain forms another four-helix bundle that assembles the two units of the heterodimer into a tetramer [1].	Domain
B, D	PF09060	L27_N (L27_N)	L27_N	The L27_N domain plays a role in the biogenesis of tight junctions and in the establishment of cell polarity in epithelial cells. Each L27_N domain consists of three alpha-helices, the first two of which form an antiparallel coiled-coil. Two L27 doma ...	The L27_N domain plays a role in the biogenesis of tight junctions and in the establishment of cell polarity in epithelial cells. Each L27_N domain consists of three alpha-helices, the first two of which form an antiparallel coiled-coil. Two L27 domains come together to form a four-helical bundle with the antiparallel coiled-coils formed by the first two helices. The third helix of each domain forms another coiled-coil packing at one end of the four-helix bundle, creating a large hydrophobic interface: the hydrophobic interactions are the major force that drives heterodimer formation [1].	Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A, C	protein associated to tight junctions	-	regulation of cytoskeleton organization regulation of biological process regulation of cellular component organization regulation of cellular process microtubule cytoskeleton organization biological regulation regulation of microtubule-based process regulation of organelle organization cellular component organization organelle organization cellular process microtubule-based process cellular component organization or biogenesis regulation of microtubule cytoskeleton organization regulation of cytoskeleton organization regulation of biological process regulation of cellular component organization regulation of cellular process microtubule cytoskeleton organization biological regulation regulation of microtubule-based process regulation of organelle organization cellular component organization organelle organization cellular process microtubule-based process cellular component organization or biogenesis regulation of microtubule cytoskeleton organization cytoskeleton organization protein localization cellular localization establishment of protein localization nitrogen compound transport transport organic substance transport intracellular transport establishment of localization localization protein transport establishment of localization in cell cellular macromolecule localization macromolecule localization intracellular protein transport microtubule organizing center organization developmental process multicellular organismal process plasma membrane bounded cell projection organization cellular developmental process cell projection organization cell development neuron projection development nervous system development generation of neurons neurogenesis multicellular organism development neuron differentiation dendrite development cell differentiation neuron development anatomical structure development system development tight junction organization cellular component biogenesis cell junction organization cellular component assembly tight junction assembly cell junction assembly cell-cell junction assembly cell-cell junction organization cell adhesion myelination axon ensheathment ensheathment of neurons cellular response to stimulus response to stimulus signaling signal transduction intracellular signal transduction cell communication	cellular anatomical entity endomembrane system apical part of cell cell periphery membrane plasma membrane plasma membrane region apical plasma membrane cell-cell junction protein-containing complex plasma membrane protein complex anchoring junction membrane protein complex apical junction complex cellular anatomical entity endomembrane system apical part of cell cell periphery membrane plasma membrane plasma membrane region apical plasma membrane cell-cell junction protein-containing complex plasma membrane protein complex anchoring junction membrane protein complex apical junction complex cell junction subapical complex somatodendritic compartment cell projection dendrite dendritic tree neuron projection plasma membrane bounded cell projection intracellular anatomical structure cytoplasm apicolateral plasma membrane synapse glutamatergic synapse membrane-bounded organelle intracellular organelle cytoplasmic vesicle organelle intracellular vesicle intracellular membrane-bounded organelle vesicle compact myelin myelin sheath Schmidt-Lanterman incisure postsynaptic density postsynapse neuron to neuron synapse postsynaptic specialization asymmetric synapse bicellular tight junction tight junction
B, D	MAGUK p55 subfamily member 5	protein binding binding protein domain specific binding adenyl ribonucleotide binding nucleotide binding purine ribonucleotide binding purine ribonucleoside triphosphate binding nucleoside phosphate binding ion binding purine nucleotide binding organic cyclic compound binding anion binding adenyl nucleotide binding ATP binding protein binding binding protein domain specific binding adenyl ribonucleotide binding nucleotide binding purine ribonucleotide binding purine ribonucleoside triphosphate binding nucleoside phosphate binding ion binding purine nucleotide binding organic cyclic compound binding anion binding adenyl nucleotide binding ATP binding heterocyclic compound binding carbohydrate derivative binding ribonucleotide binding small molecule binding identical protein binding	developmental process multicellular organismal process cellular developmental process central nervous system neuron development cell development nervous system development generation of neurons central nervous system neuron differentiation multicellular organism development neurogenesis central nervous system development neuron differentiation cell differentiation neuron development anatomical structure development developmental process multicellular organismal process cellular developmental process central nervous system neuron development cell development nervous system development generation of neurons central nervous system neuron differentiation multicellular organism development neurogenesis central nervous system development neuron differentiation cell differentiation neuron development anatomical structure development cellular process system development tissue morphogenesis anatomical structure morphogenesis epithelium development morphogenesis of an epithelium tissue development morphogenesis of an epithelial sheet cellular response to stimulus cellular response to growth factor stimulus cell surface receptor protein serine/threonine kinase signaling pathway regulation of cellular process response to stimulus signaling cellular response to transforming growth factor beta stimulus regulation of transmembrane receptor protein serine/threonine kinase signaling pathway regulation of signal transduction regulation of transforming growth factor beta receptor signaling pathway cell communication cellular response to endogenous stimulus signal transduction enzyme-linked receptor protein signaling pathway regulation of biological process regulation of signaling cell surface receptor signaling pathway regulation of cellular response to transforming growth factor beta stimulus response to endogenous stimulus regulation of cellular response to growth factor stimulus biological regulation response to transforming growth factor beta regulation of response to stimulus transforming growth factor beta receptor signaling pathway regulation of cell communication response to growth factor transforming growth factor beta receptor superfamily signaling pathway cellular component assembly involved in morphogenesis myelin assembly cellular component organization cellular component biogenesis myelination cellular anatomical entity morphogenesis cellular component assembly axon ensheathment ensheathment of neurons anatomical structure formation involved in morphogenesis cellular component organization or biogenesis protein localization localization protein localization to cell periphery cellular localization protein localization to plasma membrane cellular macromolecule localization macromolecule localization localization within membrane protein localization to membrane morphogenesis of embryonic epithelium embryonic morphogenesis establishment or maintenance of cell polarity embryo development establishment or maintenance of polarity of embryonic epithelium head development forebrain development animal organ development brain development pallium development cerebral cortex development telencephalon development organic substance metabolic process biosynthetic process cellular biosynthetic process cellular metabolic process organic substance biosynthetic process metabolic process macromolecule metabolic process gene expression macromolecule biosynthetic process protein localization to myelin sheath abaxonal region peripheral nervous system axon ensheathment glial cell development gliogenesis plasma membrane organization myelination in peripheral nervous system peripheral nervous system myelin maintenance Schwann cell differentiation endomembrane system organization membrane organization peripheral nervous system development Schwann cell development glial cell differentiation myelin maintenance establishment or maintenance of bipolar cell polarity establishment or maintenance of epithelial cell apical/basal polarity establishment or maintenance of apical/basal cell polarity	somatodendritic compartment cell body perikaryon neuronal cell body cellular anatomical entity cell periphery apical part of cell membrane plasma membrane plasma membrane region apical plasma membrane extracellular exosome membrane-bounded organelle extracellular vesicle somatodendritic compartment cell body perikaryon neuronal cell body cellular anatomical entity cell periphery apical part of cell membrane plasma membrane plasma membrane region apical plasma membrane extracellular exosome membrane-bounded organelle extracellular vesicle extracellular organelle extracellular region organelle extracellular space vesicle extracellular membrane-bounded organelle myelin sheath adaxonal region myelin sheath intracellular anatomical structure cytoplasm protein-containing complex apical junction complex cell-cell junction anchoring junction cell junction adherens junction intracellular organelle Golgi apparatus intracellular membrane-bounded organelle endomembrane system compact myelin Schmidt-Lanterman incisure bounding membrane of organelle endoplasmic reticulum-Golgi intermediate compartment membrane endoplasmic reticulum-Golgi intermediate compartment organelle membrane bicellular tight junction tight junction axon cell projection neuron projection plasma membrane bounded cell projection lateral loop

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A, C	IPR004172	L27 domain	Domain
A, C	IPR036034	PDZ superfamily	Homologous Superfamily
A, C	IPR036892	L27 domain superfamily	Homologous Superfamily
A, C	IPR032078	Multiple PDZ domain protein, unstructured region	Domain
A, C	IPR001478	PDZ domain	Domain
A, C	IPR015132	L27-2	Domain
B, D	IPR008145	Guanylate kinase/L-type calcium channel beta subunit	Domain
B, D	IPR004172	L27 domain	Domain
B, D	IPR014775	L27 domain, C-terminal	Domain
B, D	IPR015145	L27-N	Domain
B, D	IPR036028	SH3-like domain superfamily	Homologous Superfamily
B, D	IPR020590	Guanylate kinase, conserved site	Conserved Site
B, D	IPR035601	MPP5, SH3 domain	Domain
B, D	IPR027417	P-loop containing nucleoside triphosphate hydrolase	Homologous Superfamily
B, D	IPR036034	PDZ superfamily	Homologous Superfamily
B, D	IPR001452	SH3 domain	Domain
B, D	IPR036892	L27 domain superfamily	Homologous Superfamily
B, D	IPR008144	Guanylate kinase-like domain	Domain
B, D	IPR001478	PDZ domain	Domain

Pharos: Disease Associations Pharos Homepage Annotation

Chains	Drug Target	Associated Disease
B, D	Pharos: Q8N3R9	atypical teratoid rhabdoid tumor malignant ependymoma ulcerative colitis interstitial cystitis medulloblastoma large cell medulloblastoma ovarian cancer

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.