2IE3 image
Entry Detail
PDB ID:
2IE3
Keywords:
Title:
Structure of the Protein Phosphatase 2A Core Enzyme Bound to Tumor-inducing Toxins
Biological Source:
Source Organism:
Host Organism:
PDB Version:
Deposition Date:
2006-09-17
Release Date:
2006-11-07
Method Details:
Experimental Method:
Resolution:
2.80 Å
R-Value Free:
0.26
R-Value Work:
0.22
R-Value Observed:
0.25
Space Group:
I 2 2 2
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Protein Phosphatase 2, regulatory subunit A (PR 65), alpha isoform
Chain IDs:A
Chain Length:589
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Description:Serine/threonine-protein phosphatase 2A catalytic subunit alpha isoform
Chain IDs:B (auth: C)
Chain Length:309
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Description:microcystin LR
Chain IDs:C (auth: I)
Chain Length:7
Number of Molecules:1
Biological Source:Cyanobacteria
Ligand Molecules
Peptide-like Molecules
PRD_000212
Primary Citation
Structure of Protein Phosphatase 2A Core Enzyme Bound to Tumor-Inducing Toxins
Cell(Cambridge,Mass.) 127 341 353 (2006)
PMID: 17055435 DOI: 10.1016/j.cell.2006.09.025

Abstact

The serine/threonine phosphatase protein phosphatase 2A (PP2A) plays an essential role in many aspects of cellular functions and has been shown to be an important tumor suppressor. The core enzyme of PP2A comprises a 65 kDa scaffolding subunit and a 36 kDa catalytic subunit. Here we report the crystal structures of the PP2A core enzyme bound to two of its inhibitors, the tumor-inducing agents okadaic acid and microcystin-LR, at 2.6 and 2.8 A resolution, respectively. The catalytic subunit recognizes one end of the elongated scaffolding subunit by interacting with the conserved ridges of HEAT repeats 11-15. Formation of the core enzyme forces the scaffolding subunit to undergo pronounced structural rearrangement. The scaffolding subunit exhibits considerable conformational flexibility, which is proposed to play an essential role in PP2A function. These structures, together with biochemical analyses, reveal significant insights into PP2A function and serve as a framework for deciphering the diverse roles of PP2A in cellular physiology.

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