2NPP image
Entry Detail
PDB ID:
2NPP
Title:
Structure of the Protein Phosphatase 2A Holoenzyme
Biological Source:
Source Organism:
Host Organism:
PDB Version:
Deposition Date:
2006-10-28
Release Date:
2006-12-12
Method Details:
Experimental Method:
Resolution:
3.30 Å
R-Value Free:
0.29
R-Value Work:
0.25
R-Value Observed:
0.26
Space Group:
P 21 21 21
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Protein Phosphatase 2, regulatory subunit A (PR 65), alpha isoform
Chain IDs:A, D
Chain Length:589
Number of Molecules:2
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Description:Serine/threonine-protein phosphatase 2A 56 kDa regulatory subunit gamma isoform
Chain IDs:B, E
Chain Length:449
Number of Molecules:2
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Description:Serine/threonine-protein phosphatase 2A catalytic subunit alpha isoform
Chain IDs:C, F
Chain Length:309
Number of Molecules:2
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Description:microcystin LR
Chain IDs:G (auth: X), H (auth: Y)
Chain Length:7
Number of Molecules:2
Biological Source:Cyanobacteria
Ligand Molecules
Peptide-like Molecules
PRD_000212
Primary Citation
Structure of the protein phosphatase 2A holoenzyme
Cell(Cambridge,Mass.) 127 1239 1251 (2006)
PMID: 17174897 DOI: 10.1016/j.cell.2006.11.033

Abstact

Protein Phosphatase 2A (PP2A) plays an essential role in many aspects of cellular physiology. The PP2A holoenzyme consists of a heterodimeric core enzyme, which comprises a scaffolding subunit and a catalytic subunit, and a variable regulatory subunit. Here we report the crystal structure of the heterotrimeric PP2A holoenzyme involving the regulatory subunit B'/B56/PR61. Surprisingly, the B'/PR61 subunit has a HEAT-like (huntingtin-elongation-A subunit-TOR-like) repeat structure, similar to that of the scaffolding subunit. The regulatory B'/B56/PR61 subunit simultaneously interacts with the catalytic subunit as well as the conserved ridge of the scaffolding subunit. The carboxyterminus of the catalytic subunit recognizes a surface groove at the interface between the B'/B56/PR61 subunit and the scaffolding subunit. Compared to the scaffolding subunit in the PP2A core enzyme, formation of the holoenzyme forces the scaffolding subunit to undergo pronounced conformational rearrangements. This structure reveals significant ramifications for understanding the function and regulation of PP2A.

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