Related Experiment Video
Updated: Jul 15, 2026

X-Ray Crystallography to Study the Oligomeric State Transition of the Thermotoga maritima M42 Aminopeptidase TmPep1050
Published on: May 13, 2020
Structure of the protein phosphatase 2A holoenzyme
Yanhui Xu1, Yongna Xing, Yu Chen
1Department of Molecular Biology, Lewis Thomas Laboratory, Princeton University, Princeton, NJ 08544, USA.
Abstract:
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.
More Related Videos
10:17A Mass Spectrometry-Based Approach to Identify Phosphoprotein Phosphatases and their Interactors
Published on: April 29, 2022
10:31A Liposome Membrane Permeability Assay for Investigating the Effects of Phosphatidylinositol Phosphate Groups on Membranotropic Action of Venom PLA2
Published on: September 26, 2025
Related Concept Videos
Protein Complex Assembly
Many viruses self-assemble into a fully functional unit using the infected host cell to...
Protein Kinases and Phosphatases
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
ATP Synthase: Structure
Protein Kinases and Phosphatases
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
Calmodulin-dependent Signaling
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
The Proteasome Structure
The proteasome is an...