PDBsum entry 2z5e

Chaperone

PDB id: 2z5e

Contents

Protein chain

122 a.a. *

Waters ×255

* Residue conservation analysis

PDB id:

2z5e

Name:

Chaperone

Title:

Crystal structure of proteasome assembling chaperone 3

Structure:

Proteasome assembling chaperone 3. Chain: a, b. Synonym: hypothetical protein mgc10911. Engineered: yes

Source:

Homo sapiens. Human. Organism_taxid: 9606. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.

Resolution:

2.00Å R-factor: 0.184 R-free: 0.252

Authors:

K.Okamoto,E.Kurimoto,E.Sakata,A.Suzuki,T.Yamane,Y.Hirano,S.Murata, K.Tanaka,K.Kato

Key ref:

H.Yashiroda et al. (2008). Crystal structure of a chaperone complex that contributes to the assembly of yeast 20S proteasomes. Nat Struct Mol Biol, 15, 228-236. PubMed id: 18278057 DOI: 10.1038/nsmb.1386

Date:

06-Jul-07 Release date: 19-Feb-08

Protein chains

Q9BT73  (PSMG3_HUMAN) -  Proteasome assembly chaperone 3 from Homo sapiens

Seq: 122 a.a.

Struc: 122 a.a.

Enzyme reactions

• Enzyme class: E.C.?

DOI no: 10.1038/nsmb.1386

Nat Struct Mol Biol 15:228-236 (2008)

PubMed id: 18278057

Crystal structure of a chaperone complex that contributes to the assembly of yeast 20S proteasomes.

H.Yashiroda, T.Mizushima, K.Okamoto, T.Kameyama, H.Hayashi, T.Kishimoto, S.Niwa, M.Kasahara, E.Kurimoto, E.Sakata, K.Takagi, A.Suzuki, Y.Hirano, S.Murata, K.Kato, T.Yamane, K.Tanaka.

ABSTRACT

Eukaryotic 20S proteasomes are composed of two alpha-rings and two beta-rings, which form an alphabetabetaalpha stacked structure. Here we describe a proteasome-specific chaperone complex, designated Dmp1-Dmp2, in budding yeast. Dmp1-Dmp2 directly bound to the alpha5 subunit to facilitate alpha-ring formation. In Deltadmp1 cells, alpha-rings lacking alpha4 and decreased formation of 20S proteasomes were observed. Dmp1-Dmp2 interacted with proteasome precursors early during proteasome assembly and dissociated from the precursors before the formation of half-proteasomes. Notably, the crystallographic structures of Dmp1 and Dmp2 closely resemble that of PAC3-a mammalian proteasome-assembling chaperone; nonetheless, neither Dmp1 nor Dmp2 showed obvious sequence similarity to PAC3. The structure of the Dmp1-Dmp2-alpha5 complex reveals how this chaperone functions in proteasome assembly and why it dissociates from proteasome precursors before the beta-rings are assembled.

Selected figure(s)

Figure 6.
(a) Above, a stereo ribbon diagram of the Dmp1–Dmp2 loop- 5 complex. Dmp1, Dmp2 loop and 5 are colored blue, red and cyan, respectively. Below, a ribbon diagram of the 5 (PDB ID code: 1RYP; chain E, cyan) and 5 (PDB ID code: 1RYP; chain L, green) complex. The secondary structural elements are labeled. (b) Close-up view of the Dmp1–Dmp2 loop– 5 interface showing amino acids of Dmp1 (blue), Dmp2 (red) and 5 (cyan). Hydrogen bonds are indicated by dotted lines. (c) Binding positions of the Dmp1–Dmp2 complex in the 20S proteasome. Dmp1, Dmp2 and 5 are shown as ribbon representations and are colored blue, red and cyan, respectively. C traces are colored yellow in the -ring and green in the [36]beta -ring. (d) Model of the Dmp1–Dmp2– [37]alpha -ring complex derived from the published structure of the yeast proteasome (PDB ID code: 1RYP).

Figure 7.
(a) Structure of PAC3. A ribbon diagram of the PAC3 homodimer. Molecule A and molecule B are colored dark cyan and olive, respectively. The secondary structural elements of PAC3 are labeled. (b) The structure of PAC3 (olive) is compared with the structures of Dmp1 (blue) and Dmp2 (red). The secondary structural elements are labeled. (c) Topology diagram of PAC3. -Helices and -strands are represented by cylinders and arrows, respectively.

The above figures are reprinted by permission from Macmillan Publishers Ltd: Nat Struct Mol Biol (2008, 15, 228-236) copyright 2008.

Figures were selected by the author.