Annotations: 1G3K

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

Chains	Domain Info	Class	Fold	Superfamily	Family	Domain	Species	Provenance Source (Version)
A	d1g3ka_	Alpha and beta proteins (a+b)	Ntn hydrolase-like	N-terminal nucleophile aminohydrolases (Ntn hydrolases)	Proteasome subunits	HslV (ClpQ) protease	(Haemophilus influenzae ) [TaxId: 727 ],	SCOPe (2.08)
B	d1g3kb_	Alpha and beta proteins (a+b)	Ntn hydrolase-like	N-terminal nucleophile aminohydrolases (Ntn hydrolases)	Proteasome subunits	HslV (ClpQ) protease	(Haemophilus influenzae ) [TaxId: 727 ],	SCOPe (2.08)
C	d1g3kc_	Alpha and beta proteins (a+b)	Ntn hydrolase-like	N-terminal nucleophile aminohydrolases (Ntn hydrolases)	Proteasome subunits	HslV (ClpQ) protease	(Haemophilus influenzae ) [TaxId: 727 ],	SCOPe (2.08)

Domain Annotation: SCOP2 Classification SCOP2 Database Homepage

Chains	Type	Family Name	Domain Identifier	Family Identifier	Provenance Source (Version)
A	SCOP2 Family	Proteasome subunits	8024524	4002254	SCOP2 (2022-06-29)
A	SCOP2 Superfamily	Class II glutamine amidotransferases	8036903	3000131	SCOP2 (2022-06-29)
B	SCOP2B Superfamily	Class II glutamine amidotransferases	8036903	3000131	SCOP2B (2022-06-29)
C	SCOP2B Superfamily	Class II glutamine amidotransferases	8036903	3000131	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	Proteasome	e1g3kA1	A: a+b four layers	X: Ntn/PP2C	H: Ntn	T: Proteasome subunits	F: Proteasome	ECOD (1.6)
B	Proteasome	e1g3kB1	A: a+b four layers	X: Ntn/PP2C	H: Ntn	T: Proteasome subunits	F: Proteasome	ECOD (1.6)
C	Proteasome	e1g3kC1	A: a+b four layers	X: Ntn/PP2C	H: Ntn	T: Proteasome subunits	F: Proteasome	ECOD (1.6)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
A	3.60.20.10	Alpha Beta	4-Layer Sandwich	Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1	Aminohydrolase, N-terminal nucleophile (Ntn) domain	CATH (4.3.0)
B	3.60.20.10	Alpha Beta	4-Layer Sandwich	Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1	Aminohydrolase, N-terminal nucleophile (Ntn) domain	CATH (4.3.0)
C	3.60.20.10	Alpha Beta	4-Layer Sandwich	Glutamine Phosphoribosylpyrophosphate, subunit 1, domain 1	Aminohydrolase, N-terminal nucleophile (Ntn) domain	CATH (4.3.0)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
A, B, C	PF00227	Proteasome subunit (Proteasome)	Proteasome subunit	The proteasome is a multisubunit structure that degrades proteins. Protein degradation is an essential component of regulation because proteins can become misfolded, damaged, or unnecessary. Proteasomes and their homologues vary greatly in complexity ...	The proteasome is a multisubunit structure that degrades proteins. Protein degradation is an essential component of regulation because proteins can become misfolded, damaged, or unnecessary. Proteasomes and their homologues vary greatly in complexity: from HslV (heat shock locus v), which is encoded by 1 gene in bacteria, to the eukaryotic 20S proteasome, which is encoded by more than 14 genes [1]. Recently evidence of two novel groups of bacterial proteasomes was proposed. The first is Anbu, which is sparsely distributed among cyanobacteria and proteobacteria [1]. The second is call beta-proteobacteria proteasome homologue (BPH) [1].	Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A, B, C	ATP-DEPENDENT PROTEASE HSLV	peptidase activity catalytic activity, acting on a protein threonine-type peptidase activity hydrolase activity catalytic activity endopeptidase activity threonine-type endopeptidase activity cation binding ion binding binding metal ion binding small molecule binding	catabolic process proteolysis involved in protein catabolic process proteolysis metabolic process cellular process primary metabolic process protein catabolic process protein metabolic process macromolecule metabolic process macromolecule catabolic process	cellular anatomical structure intracellular anatomical structure cytoplasm protein-containing complex catalytic complex peptidase complex cytosolic proteasome complex HslUV protease complex proteasome complex endopeptidase complex cytosol intracellular protein-containing complex proteasome core complex

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A, B, C	IPR023333	Proteasome B-type subunit	Family
A, B, C	IPR029055	Nucleophile aminohydrolases, N-terminal	Homologous Superfamily
A, B, C	IPR001353	Proteasome, subunit alpha/beta	Family
A, B, C	IPR022281	ATP-dependent protease subunit HslV	Family

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.