P28061 (PSB_THEAC) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
Proteasome subunit beta
EC=3.4.25.1

Alternative name(s):
20S proteasome beta subunit
Proteasome core protein PsmB

Gene names

Name:	psmB
Ordered Locus Names:	Ta0612

Organism

Thermoplasma acidophilum (strain ATCC 25905 / DSM 1728 / JCM 9062 / NBRC 15155 / AMRC-C165)

Taxonomic identifier

273075 [NCBI]

Taxonomic lineage

Archaea › Euryarchaeota › Thermoplasmata › Thermoplasmatales › Thermoplasmataceae › Thermoplasma

Protein attributes

Sequence length	211 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is further processed into a mature form.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	Component of the proteasome core, a large protease complex with broad specificity involved in protein degradation. The T.acidophilum proteasome is able to cleave oligopeptides after Tyr, Leu, Phe, and to a lesser extent after Glu and Arg. Thus, displays chymotrypsin-like activity and low level of caspase-like and trypsin-like activities. Ref.3
Catalytic activity	Cleavage of peptide bonds with very broad specificity. Ref.3
Enzyme regulation	The formation of the proteasomal ATPase PAN-20S proteasome complex, via the docking of the C-termini of PAN into the intersubunit pockets in the alpha-rings, triggers opening of the gate for substrate entry. Interconversion between the open-gate and close-gate conformations leads to a dynamic regulation of the 20S proteasome proteolysis activity. Ref.9 Ref.15
Subunit structure	The 20S proteasome core is composed of 14 alpha and 14 beta subunits that assemble into four stacked heptameric rings, resulting in a barrel-shaped structure. The two inner rings, each composed of seven catalytic beta subunits, are sandwiched by two outer rings, each composed of seven alpha subunits. The catalytic chamber with the active sites is on the inside of the barrel. Has a gated structure, the ends of the cylinder being occluded by the N-termini of the alpha-subunits. Is capped at one or both ends by the proteasome regulatory ATPase, PAN. Ref.4 Ref.8 Ref.10 Ref.11 Ref.13 Ref.14
Subcellular location	Cytoplasm By similarity HAMAP MF_02113_A.
Miscellaneous	The configuration of the closed gate contains an opening large enough to allow rapid entry of tetrapeptides but able to impede the entry of proteins and longer peptides. HAMAP MF_02113_A
Sequence similarities	Belongs to the peptidase T1B family.
Biophysicochemical properties	Kinetic parameters: KM=39 µM for Suc-LLVY-Amc (at 55 degrees Celsius) Ref.3 Vmax=28 nmol/min/mg enzyme with Suc-LLVY-Amc as substrate (at 55 degrees Celsius)

Ontologies

Keywords
Cellular component	Cytoplasm Proteasome
Molecular function	Hydrolase Protease Threonine protease
PTM	Autocatalytic cleavage Zymogen
Technical term	3D-structure Complete proteome Direct protein sequencing Reference proteome
Gene Ontology (GO)
Biological process	proteasomal protein catabolic process Inferred from direct assay Ref.3. Source: UniProtKB
Cellular component	cytoplasm Inferred from electronic annotation. Source: UniProtKB-SubCell proteasome core complex, beta-subunit complex Inferred from direct assay Ref.13Ref.10Ref.3. Source: UniProtKB
Molecular function	threonine-type endopeptidase activity Inferred from direct assay Ref.5. Source: UniProtKB
Complete GO annotation...

Sequence annotation (Features)

Feature key

Position(s)

Length

Description

Graphical view

Feature identifier

Molecule processing

Propeptide

1 – 8

8

Removed in mature form; by autocatalysis HAMAP MF_02113_A

PRO_0000026675

Chain

9 – 211

203

Proteasome subunit beta HAMAP MF_02113_A

PRO_0000026676

Sites

Active site

9

1

Nucleophile Ref.5

Experimental info

Mutagenesis

9

1

T → S: No effect on catalytic activity. Ref.5

Secondary structure

1

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211

Helix Strand Turn

Details...

Beta strand

11 – 16

6

Beta strand

19 – 24

6

Beta strand

28 – 30

3

Beta strand

33 – 37

5

Beta strand

42 – 46

5

Beta strand

49 – 55

7

Helix

57 – 78

22

Helix

84 – 97

14

Turn

98 – 100

3

Beta strand

105 – 121

17

Beta strand

127 – 136

10

Helix

139 – 149

11

Helix

156 – 173

18

Beta strand

182 – 187

6

Turn

188 – 190

3

Beta strand

191 – 194

4

Helix

197 – 206

10

Sequences

	Sequence		Length	Mass (Da)
	P28061 [UniParc]. Last modified August 1, 1992. Version 1. Checksum: F81B9360641873DD	FASTA	211	23,147
	10 20 30 40 50 60 MNQTLETGTT TVGITLKDAV IMATERRVTM ENFIMHKNGK KLFQIDTYTG MTIAGLVGDA 70 80 90 100 110 120 QVLVRYMKAE LELYRLQRRV NMPIEAVATL LSNMLNQVKY MPYMVQLLVG GIDTAPHVFS 130 140 150 160 170 180 IDAAGGSVED IYASTGSGSP FVYGVLESQY SEKMTVDEGV DLVIRAISAA KQRDSASGGM 190 200 210 IDVAVITRKD GYVQLPTDQI ESRIRKLGLI L

References

	« Hide 'large scale' referencesShow 'large scale' references »
[1]	"Primary structure of the Thermoplasma proteasome and its implications for the structure, function, and evolution of the multicatalytic proteinase." Zwickl P., Grziwa A., Puehler G., Dahlmann B., Lottspeich F., Baumeister W. Biochemistry 31:964-972(1992) [PubMed: 1734972] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA], PARTIAL PROTEIN SEQUENCE.
[2]	"The genome sequence of the thermoacidophilic scavenger Thermoplasma acidophilum." Ruepp A., Graml W., Santos-Martinez M.-L., Koretke K.K., Volker C., Mewes H.-W., Frishman D., Stocker S., Lupas A.N., Baumeister W. Nature 407:508-513(2000) [PubMed: 11029001] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. Strain: ATCC 25905 / DSM 1728 / JCM 9062 / NBRC 15155 / AMRC-C165.
[3]	"Processive degradation of proteins and other catalytic properties of the proteasome from Thermoplasma acidophilum." Akopian T.N., Kisselev A.F., Goldberg A.L. J. Biol. Chem. 272:1791-1798(1997) [PubMed: 8999862] [Abstract] Cited for: PROTEIN SEQUENCE OF N-TERMINUS, FUNCTION, CATALYTIC ACTIVITY, KINETIC PARAMETERS.
[4]	"Subunit stoichiometry and three-dimensional arrangement in proteasomes from Thermoplasma acidophilum." Puehler G., Weinkauf S., Bachmann L., Mueller S., Engel E., Hegerl R., Baumeister W. EMBO J. 11:1607-1616(1992) [PubMed: 1373380] [Abstract] Cited for: SUBUNIT.
[5]	"Proteasome from Thermoplasma acidophilum: a threonine protease." Seemuller E., Lupas A., Stock D., Lowe J., Huber R., Baumeister W. Science 268:579-582(1995) [PubMed: 7725107] [Abstract] Cited for: ACTIVE SITE, CATALYTIC MECHANISM, MUTAGENESIS OF THR-9.
[6]	"Autocatalytic processing of the 20S proteasome." Seemuller E., Lupas A., Baumeister W. Nature 382:468-471(1996) [PubMed: 8684489] [Abstract] Cited for: AUTOCATALYTIC PROCESSING.
[7]	"Range of sizes of peptide products generated during degradation of different proteins by archaeal proteasomes." Kisselev A.F., Akopian T.N., Goldberg A.L. J. Biol. Chem. 273:1982-1989(1998) [PubMed: 9442034] [Abstract] Cited for: CHARACTERIZATION.
[8]	"ATP binding to PAN or the 26S ATPases causes association with the 20S proteasome, gate opening, and translocation of unfolded proteins." Smith D.M., Kafri G., Cheng Y., Ng D., Walz T., Goldberg A.L. Mol. Cell 20:687-698(2005) [PubMed: 16337593] [Abstract] Cited for: INTERACTION WITH PAN, SUBUNIT, GATED STRUCTURE.
[9]	"Docking of the proteasomal ATPases' carboxyl termini in the 20S proteasome's alpha ring opens the gate for substrate entry." Smith D.M., Chang S.C., Park S., Finley D., Cheng Y., Goldberg A.L. Mol. Cell 27:731-744(2007) [PubMed: 17803938] [Abstract] Cited for: GATE OPENING MECHANISM, ENZYME REGULATION.
[10]	"Crystal structure of the 20S proteasome from the archaeon T. acidophilum at 3.4-A resolution." Lowe J., Stock D., Jap B., Zwickl P., Baumeister W., Huber R. Science 268:533-539(1995) [PubMed: 7725097] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (3.4 ANGSTROMS) IN COMPLEX WITH ALPHA SUBUNIT, SUBUNIT.
[11]	"The 1.9 A structure of a proteasome-11S activator complex and implications for proteasome-PAN/PA700 interactions." Forster A., Masters E.I., Whitby F.G., Robinson H., Hill C.P. Mol. Cell 18:589-599(2005) [PubMed: 15916965] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (1.9 ANGSTROMS) IN COMPLEX WITH ALPHA SUBUNIT AND T.BRUCEI PA26.
[12]	"Mechanism of gate opening in the 20S proteasome by the proteasomal ATPases." Rabl J., Smith D.M., Yu Y., Chang S.C., Goldberg A.L., Cheng Y. Mol. Cell 30:360-368(2008) [PubMed: 18471981] [Abstract] Cited for: STRUCTURE BY ELECTRON MICROSCOPY (6.8 ANGSTROMS) OF THE OPEN-GATE AND CLOSED-GATE CONFORMATIONS, GATE OPENING MECHANISM.
[13]	"Interactions of PAN's C-termini with archaeal 20S proteasome and implications for the eukaryotic proteasome-ATPase interactions." Yu Y., Smith D.M., Kim H.M., Rodriguez V., Goldberg A.L., Cheng Y. EMBO J. 29:692-702(2010) [PubMed: 20019667] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (4.0 ANGSTROMS) IN COMPLEX WITH THE ALPHA SUBUNIT AND THE C-TERMINUS OF PAN FROM M.JANNASCHII.
[14]	"Structural models for interactions between the 20S proteasome and its PAN/19S activators." Stadtmueller B.M., Ferrell K., Whitby F.G., Heroux A., Robinson H., Myszka D.G., Hill C.P. J. Biol. Chem. 285:13-17(2010) [PubMed: 19889631] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (2.9 ANGSTROMS) IN COMPLEX WITH ALPHA SUBUNIT AND CHIMERIC PA26 CONSTRUCTS.
[15]	"Dynamic regulation of archaeal proteasome gate opening as studied by TROSY NMR." Religa T.L., Sprangers R., Kay L.E. Science 328:98-102(2010) [PubMed: 20360109] [Abstract] Cited for: ENZYME REGULATION.
+	Additional computationally mapped references.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ

M83674 Genomic DNA. Translation: AAA72102.1.
AL445064 Genomic DNA. Translation: CAC11751.1.

PIR

A42068.

RefSeq

NP_394085.1. NC_002578.1.

3D structure databases

PDBe
RCSB PDB
PDBj

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
1PMA	X-ray	3.40	1/2/B/P/Q/R/S/T/U/V/W/X/Y/Z	1-211	[»]
1YA7	X-ray	2.30	H/I/J/K/L/M/N	1-211	[»]
1YAR	X-ray	1.90	H/I/J/K/L/M/N	1-211	[»]
1YAU	X-ray	2.40	H/I/J/K/L/M/N	1-211	[»]
3C91	electron microscopy	6.80	1/2/H/I/J/K/L/M/N/V/W/X/Y/Z	9-211	[»]
3C92	electron microscopy	6.80	1/2/H/I/J/K/L/M/N/V/W/X/Y/Z	9-211	[»]
3IPM	X-ray	4.00	H/I/J/K/L/M/N	1-211	[»]
3JRM	X-ray	2.90	H/I/J/K/L/M/N	9-211	[»]
3JSE	X-ray	2.90	H/I/J/K/L/M/N	9-211	[»]
3JTL	X-ray	3.20	H/I/J/K/L/M/N	9-211	[»]

ProteinModelPortal

P28061.

SMR

P28061. Positions 9-211.

ModBase

Search...

Protein family/group databases

MEROPS

T01.002.

Protocols and materials databases

StructuralBiologyKnowledgebase

Search...

Genome annotation databases

GeneID

1456195.

GenomeReviews

Gene locus Ta0612 in contig AL139299_GR.

KEGG

tac:Ta0612.

NMPDR

fig|273075.1.peg.607.

Phylogenomic databases

HOGENOM

HBG499923.

OMA

MKRDSAS.

PhylomeDB

P28061.

ProtClustDB

CLSK227781.

Enzyme and pathway databases

BioCyc

TACI273075:TA0612-MONOMER.

Family and domain databases

HAMAP

MF_02113_A. Proteasome_B_A.
[Tree]

InterPro

IPR019983. Pept_T1A_Psome_bsu_arc.
IPR000243. Pept_T1A_subB.
IPR016050. Proteasome_bsu_CS.
IPR001353. Proteasome_sua/b.
IPR023333. Proteasome_suB-type.
[Graphical view]

KO

K03433.

Pfam

PF00227. Proteasome. 1 hit.
[Graphical view]

PRINTS

PR00141. PROTEASOME.

TIGRFAMs

TIGR03634. Arc_protsome_B. 1 hit.

PROSITE

PS00854. PROTEASOME_B_1. 1 hit.
PS51476. PROTEASOME_B_2. 1 hit.
[Graphical view]

ProtoNet

Search...

Entry information

Entry name

PSB_THEAC

Accession

Primary (citable) accession number: P28061

Entry history

Integrated into UniProtKB/Swiss-Prot:	August 1, 1992
Last sequence update:	August 1, 1992
Last modified:	December 14, 2011
This is version 97 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Prokaryotic Protein Annotation Program