2iae
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| , resolution 3.50Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | and | ||||||
| Gene: | Ppp2r1a (Mus musculus), PPP2R5C, KIAA0044 (Homo sapiens), PPP2CA (Homo sapiens) | ||||||
| Activity: | Phosphoprotein phosphatase, with EC number 3.1.3.16 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Crystal structure of a protein phosphatase 2A (PP2A) holoenzyme.
OverviewOverview
Protein phosphatase 2A (PP2A) is a principal Ser/Thr phosphatase, the deregulation of which is associated with multiple human cancers, Alzheimer's disease and increased susceptibility to pathogen infections. How PP2A is structurally organized and functionally regulated remains unclear. Here we report the crystal structure of an AB'C heterotrimeric PP2A holoenzyme. The structure reveals that the HEAT repeats of the scaffold A subunit form a horseshoe-shaped fold, holding the catalytic C and regulatory B' subunits together on the same side. The regulatory B' subunit forms pseudo-HEAT repeats and interacts with the C subunit near the active site, thereby defining substrate specificity. The methylated carboxy-terminal tail of the C subunit interacts with a highly negatively charged region at the interface between A and B' subunits, suggesting that the C-terminal carboxyl methylation of the C subunit promotes B' subunit recruitment by neutralizing charge repulsion. Together, our structural results establish a crucial foundation for understanding PP2A assembly, substrate recruitment and regulation.
About this StructureAbout this Structure
2IAE is a Protein complex structure of sequences from Homo sapiens and Mus musculus. Full crystallographic information is available from OCA.
ReferenceReference
Crystal structure of a protein phosphatase 2A heterotrimeric holoenzyme., Cho US, Xu W, Nature. 2007 Jan 4;445(7123):53-7. Epub 2006 Nov 1. PMID:17086192
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