PDBsum entry 4g4s

Hydrolase/chaperone

PDB id: 4g4s

Contents

Protein chains

241 a.a.

246 a.a.

237 a.a.

220 a.a.

250 a.a.

235 a.a.

246 a.a.

196 a.a.

220 a.a.

203 a.a.

195 a.a.

212 a.a.

222 a.a.

233 a.a.

200 a.a.

190 a.a.

Ligands

LDZ

Metals

_MG ×8

Waters ×846

PDB id:

4g4s

Name:

Hydrolase/chaperone

Title:

Structure of proteasome-pba1-pba2 complex

Structure:

Proteasome component c7-alpha. Chain: a. Synonym: macropain subunit c7-alpha, multicatalytic endopeptidase complex c7, proteasome component y8, proteinase ysce subunit 7, scl1 suppressor protein. Engineered: yes. Proteasome component y7. Chain: b. Synonym: macropain subunit y7, multicatalytic endopeptidase complex

Source:

Saccharomyces cerevisiae. Baker's yeast. Organism_taxid: 559292. Strain: atcc 204508 / s288c. Gene: scl1, prc2, prs2, ygl011c. Expressed in: saccharomyces cerevisiae. Expression_system_taxid: 4932. Gene: pre8, prs4, yml092c. Gene: pre9, prs5, ygr135w.

Resolution:

2.49Å R-factor: 0.184 R-free: 0.232

Authors:

E.Kish-Trier,H.Robinson,B.M.Stadtmueller,C.P.Hill

Key ref:

B.M.Stadtmueller et al. (2012). Structure of a proteasome Pba1-Pba2 complex: implications for proteasome assembly, activation, and biological function. J Biol Chem, 287, 37371-37382. PubMed id: 22930756

Date:

16-Jul-12 Release date: 05-Sep-12

Protein chain

P21243  (PSA1_YEAST) -  Proteasome subunit alpha type-1 from Saccharomyces cerevisiae (strain ATCC 204508 / S288c)

Seq: 252 a.a.

Struc: 241 a.a.

Protein chain

P23639  (PSA2_YEAST) -  Proteasome subunit alpha type-2 from Saccharomyces cerevisiae (strain ATCC 204508 / S288c)

Seq: 250 a.a.

Struc: 246 a.a.

Protein chain

P23638  (PSA3_YEAST) -  Proteasome subunit alpha type-3 from Saccharomyces cerevisiae (strain ATCC 204508 / S288c)

Seq: 258 a.a.

Struc: 237 a.a.

Protein chain

P40303  (PSA4_YEAST) -  Proteasome subunit alpha type-4 from Saccharomyces cerevisiae (strain ATCC 204508 / S288c)

Seq: 254 a.a.

Struc: 220 a.a.

Protein chain

P32379  (PSA5_YEAST) -  Proteasome subunit alpha type-5 from Saccharomyces cerevisiae (strain ATCC 204508 / S288c)

Seq: 260 a.a.

Struc: 249 a.a.

Protein chain

P40302  (PSA6_YEAST) -  Proteasome subunit alpha type-6 from Saccharomyces cerevisiae (strain ATCC 204508 / S288c)

Seq: 234 a.a.

Struc: 234 a.a.

Protein chain

P21242  (PSA7_YEAST) -  Probable proteasome subunit alpha type-7 from Saccharomyces cerevisiae (strain ATCC 204508 / S288c)

Seq: 288 a.a.

Struc: 246 a.a.

Protein chain

P38624  (PSB1_YEAST) -  Proteasome subunit beta type-1 from Saccharomyces cerevisiae (strain ATCC 204508 / S288c)

Seq: 215 a.a.

Struc: 196 a.a.

Protein chain

P25043  (PSB2_YEAST) -  Proteasome subunit beta type-2 from Saccharomyces cerevisiae (strain ATCC 204508 / S288c)

Seq: 261 a.a.

Struc: 220 a.a.

Protein chain

P25451  (PSB3_YEAST) -  Proteasome subunit beta type-3 from Saccharomyces cerevisiae (strain ATCC 204508 / S288c)

Seq: 205 a.a.

Struc: 203 a.a.

Protein chain

P22141  (PSB4_YEAST) -  Proteasome subunit beta type-4 from Saccharomyces cerevisiae (strain ATCC 204508 / S288c)

Seq: 198 a.a.

Struc: 195 a.a.

Protein chain

P30656  (PSB5_YEAST) -  Proteasome subunit beta type-5 from Saccharomyces cerevisiae (strain ATCC 204508 / S288c)

Seq: 287 a.a.

Struc: 212 a.a.

Protein chain

P23724  (PSB6_YEAST) -  Proteasome subunit beta type-6 from Saccharomyces cerevisiae (strain ATCC 204508 / S288c)

Seq: 241 a.a.

Struc: 222 a.a.

Protein chain

P30657  (PSB7_YEAST) -  Proteasome subunit beta type-7 from Saccharomyces cerevisiae (strain ATCC 204508 / S288c)

Seq: 266 a.a.

Struc: 233 a.a.

Protein chain

Q05778  (POC1_YEAST) -  Proteasome chaperone 1 from Saccharomyces cerevisiae (strain ATCC 204508 / S288c)

Seq: 276 a.a.

Struc: 200 a.a.

Protein chain

P36040  (POC2_YEAST) -  Proteasome assembly chaperone 2 from Saccharomyces cerevisiae (strain ATCC 204508 / S288c)

Seq: 267 a.a.

Struc: 190 a.a.

Enzyme reactions

• Enzyme class: Chains A, B, C, D, E, F, G, H, I, J, K, L, M, N: E.C.3.4.25.1 - proteasome endopeptidase complex.
• Reaction: Cleavage at peptide bonds with very broad specificity.

J Biol Chem 287:37371-37382 (2012)

PubMed id: 22930756

Structure of a proteasome Pba1-Pba2 complex: implications for proteasome assembly, activation, and biological function.

B.M.Stadtmueller, E.Kish-Trier, K.Ferrell, C.N.Petersen, H.Robinson, D.G.Myszka, D.M.Eckert, T.Formosa, C.P.Hill.

ABSTRACT

The 20S proteasome is an essential, 28-subunit protease that sequesters proteolytic sites within a central chamber, thereby repressing substrate degradation until proteasome activators open the entrance/exit gate. Two established activators, Blm10 and PAN/19S, induce gate opening by binding to the pockets between proteasome α-subunits using C-terminal HbYX (hydrophobic-tyrosine-any residue) motifs. Equivalent HbYX motifs have been identified in Pba1 and Pba2, which function in proteasome assembly. Here, we demonstrate that Pba1-Pba2 proteins form a stable heterodimer that utilizes its HbYX motifs to bind mature 20S proteasomes in vitro and that the Pba1-Pba2 HbYX motifs are important for a physiological function of proteasomes, the maintenance of mitochondrial function. Other factors that contribute to proteasome assembly or function also act in the maintenance of mitochondrial function and display complex genetic interactions with one another, possibly revealing an unexpected pathway of mitochondrial regulation involving the Pba1-Pba2 proteasome interaction. Our determination of a proteasome Pba1-Pba2 crystal structure reveals a Pba1 HbYX interaction that is superimposable with those of known activators, a Pba2 HbYX interaction that is different from those reported previously, and a gate structure that is disrupted but not sufficiently open to allow entry of even small peptides. These findings extend understanding of proteasome interactions with HbYX motifs and suggest multiple roles for Pba1-Pba2 interactions throughout proteasome assembly and function.