Annotations: 1BH2

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

Chains	Domain Info	Class	Fold	Superfamily	Family	Domain	Species	Provenance Source (Version)
A	d1bh2a1	All alpha proteins	Transducin (alpha subunit), insertion domain	Transducin (alpha subunit), insertion domain	Transducin (alpha subunit), insertion domain	Transducin (alpha subunit), insertion domain	Norway rat (Rattus norvegicus ) [TaxId: 10116 ],	SCOPe (2.08)
A	d1bh2a2	Alpha and beta proteins (a/b)	P-loop containing nucleoside triphosphate hydrolases	P-loop containing nucleoside triphosphate hydrolases	G proteins	Transducin (alpha subunit)	Norway rat (Rattus norvegicus ) [TaxId: 10116 ],	SCOPe (2.08)

Domain Annotation: SCOP2 Classification SCOP2 Database Homepage

Chains	Type	Family Name	Domain Identifier	Family Identifier	Provenance Source (Version)
A	SCOP2B Superfamily	Ras-like P-loop GTPases	8019719	3002022	SCOP2B (2022-06-29)
A	SCOP2B Superfamily	Galpha insert domain-like	8056777	3000669	SCOP2B (2022-06-29)
A	SCOP2B Superfamily	Ras-like P-loop GTPases	8019719	3002022	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	G-alpha	e1bh2A1	A: alpha arrays	X: Transducin (alpha subunit), insertion domain (From Topology)	H: Transducin (alpha subunit), insertion domain (From Topology)	T: Transducin (alpha subunit), insertion domain	F: G-alpha	ECOD (1.6)
A	Ras	e1bh2A2	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)

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 (4.3.0)
A	1.10.400.10	Mainly Alpha	Orthogonal Bundle	GI Alpha 1, domain 2-like	GI Alpha 1, domain 2-like	CATH (4.3.0)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
A	PF00503	G-protein alpha subunit (G-alpha)	G-protein alpha subunit	G proteins couple receptors of extracellular signals to intracellular signaling pathways. The G protein alpha subunit binds guanyl nucleotide and is a weak GTPase. A set of residues that are unique to G-alpha as compared to its ancestor the Arf-like ...	G proteins couple receptors of extracellular signals to intracellular signaling pathways. The G protein alpha subunit binds guanyl nucleotide and is a weak GTPase. A set of residues that are unique to G-alpha as compared to its ancestor the Arf-like family form a ring of residues centered on the nucleotide binding site [3]. A Ggamma is found fused to an inactive Galpha in the Dictyostelium protein gbqA [3].	Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A	GUANINE NUCLEOTIDE-BINDING PROTEIN	D2 dopamine receptor binding protein binding binding signaling receptor binding G protein-coupled receptor binding dopamine receptor binding GTPase activating protein binding guanyl nucleotide binding GTP binding nucleotide binding guanyl ribonucleotide binding purine ribonucleotide binding purine ribonucleoside triphosphate binding nucleoside phosphate binding D2 dopamine receptor binding protein binding binding signaling receptor binding G protein-coupled receptor binding dopamine receptor binding GTPase activating protein binding guanyl nucleotide binding GTP binding nucleotide binding guanyl ribonucleotide binding purine ribonucleotide binding purine ribonucleoside triphosphate binding nucleoside phosphate binding ion binding organic cyclic compound binding purine nucleotide binding anion binding heterocyclic compound binding carbohydrate derivative binding ribonucleotide binding small molecule binding cation binding magnesium ion binding metal ion binding GDP binding G protein-coupled serotonin receptor binding protein-containing complex binding G-protein beta/gamma-subunit 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	cellular process cell division cellular response to stimulus regulation of biological process regulation of cellular process response to stimulus signaling biological regulation cell communication adenylate cyclase-modulating G protein-coupled receptor signaling pathway G protein-coupled receptor signaling pathway signal transduction cell cycle regulation of cytoskeleton organization cellular process cell division cellular response to stimulus regulation of biological process regulation of cellular process response to stimulus signaling biological regulation cell communication adenylate cyclase-modulating G protein-coupled receptor signaling pathway G protein-coupled receptor signaling pathway signal transduction cell cycle regulation of cytoskeleton organization regulation of cellular component organization microtubule cytoskeleton organization regulation of mitotic spindle organization mitotic cell cycle cellular component organization cellular component organization or biogenesis regulation of cell cycle microtubule cytoskeleton organization involved in mitosis spindle organization cell cycle process regulation of cell cycle process regulation of microtubule-based process regulation of spindle organization regulation of organelle organization mitotic spindle organization organelle organization mitotic cell cycle process microtubule-based process cytoskeleton organization regulation of microtubule cytoskeleton organization protein localization positive regulation of protein localization to cell periphery regulation of localization protein localization to cell periphery cellular localization regulation of protein localization positive regulation of biological process positive regulation of protein localization to cell cortex regulation of protein localization to cell periphery localization regulation of cellular localization regulation of protein localization to cell cortex cellular macromolecule localization macromolecule localization positive regulation of protein localization protein localization to cell cortex positive regulation of cellular process trans-synaptic signaling regulation of signaling negative regulation of signaling modulation of chemical synaptic transmission negative regulation of biological process cell-cell signaling negative regulation of synaptic transmission negative regulation of cell communication chemical synaptic transmission synaptic signaling regulation of trans-synaptic signaling anterograde trans-synaptic signaling negative regulation of cellular process regulation of cell communication regulation of signal transduction intracellular signal transduction cAMP-mediated signaling regulation of intracellular signal transduction regulation of response to stimulus intracellular signaling cassette regulation of cAMP-mediated signaling response to organic substance response to ketone response to lipid response to alcohol cellular response to forskolin cellular response to organic cyclic compound response to oxygen-containing compound cellular response to oxygen-containing compound cellular response to chemical stimulus cellular response to alcohol response to chemical response to forskolin cellular response to lipid cellular response to organic substance cellular response to ketone response to organic cyclic compound	midbody cellular anatomical entity cell periphery cell cortex intracellular anatomical structure cytoplasm protein-containing complex extrinsic component of plasma membrane catalytic complex plasma membrane protein complex cytoplasmic side of membrane membrane plasma membrane membrane protein complex midbody cellular anatomical entity cell periphery cell cortex intracellular anatomical structure cytoplasm protein-containing complex extrinsic component of plasma membrane catalytic complex plasma membrane protein complex cytoplasmic side of membrane membrane plasma membrane membrane protein complex heterotrimeric G-protein complex side of membrane cytoplasmic side of plasma membrane GTPase complex extrinsic component of membrane extrinsic component of cytoplasmic side of plasma membrane intracellular organelle centrosome microtubule organizing center cytoskeleton organelle intracellular non-membrane-bounded organelle microtubule cytoskeleton non-membrane-bounded organelle membrane-bounded organelle nucleus intracellular membrane-bounded organelle

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A	IPR001019	Guanine nucleotide binding protein (G-protein), alpha subunit	Family
A	IPR011025	G protein alpha subunit, helical insertion	Homologous Superfamily
A	IPR027417	P-loop containing nucleoside triphosphate hydrolase	Homologous Superfamily
A	IPR001408	G-protein alpha subunit, group I	Family

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

Chains	Enzyme Name	Description	Catalytic Residues
A	G-protein alpha subunit, group I (GTPase) M-CSA #533	The alpha subunits of heterotrimeric G proteins are members of the Ras superfamily of GTP hydrolases and function in signal transduction. They are activated by replacement of bound GDP by GTP, a process promoted by activated 7-transmembrane receptors, and by subsequent dissociation of the alpha subunit from the beta and gamma subunits. The G-alpha subunit remains active until its GTPase activity converts the bound GTP back to GDP. The alpha subunit of the G protein Gi1 is expressed in many different tissues and is activated by the alpha-2 adrenergic and M-2 muscarinic cholinergic receptors, amongst others. Its downstream effectors include particular isoforms of adenylate cyclase; types V and VI are particularly sensitive to inhibition by G-alpha-i1. The mechanism of enzymatic GTP hydrolysis (and similar phosphoryl transfer reactions) has been subject to significant debate and still remains to be firmly established. More recent models have proposed a dissociative-like process, in which the transition state shows significant cleavage of the gamma-beta phosphoanhydride bond and relatively little bond formation between the gamma phosphate and the nucleophilic water molecule. (See, for example, the reference pubmed ID 15236956 for a recent discussion).	Defined by 5 residues: GLU:A-12 [auth A-43]THR:A-17 [auth A-48]ARG:A-147 [auth A-178]ASP:A-169 [auth A-200]GLN:A-173 [auth A-204] \| Explore in 3D: M-CSA Motif Definition Search M-CSA Motif

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.