2V0P

The Structure of Tap42 Alpha4 Subunit

Summary for 2V0P

• Entry DOI: 10.2210/pdb2v0p/pdb
• Descriptor: TYPE 2A PHOSPHATASE-ASSOCIATED PROTEIN 42, ZINC ION (3 entities in total)
• Functional Keywords: phosphorylation, signal transduction inhibitor, hydrolase inhibitor
• Biological source: SACCHAROMYCES CEREVISIAE (BAKER'S YEAST)
• Total number of polymer chains: 2
• Total formula weight: 55395.27

Authors

Roe, S.M.,Yang, J.,Barford, D. (deposition date: 2007-05-15, release date: 2007-07-17, Last modification date: 2024-11-06)

Primary citation

Yang, J.,Roe, S.M.,Prickett, T.D.,Brautigan, D.L.,Barford, D.
The Structure of Tap42/Alpha4 Reveals a Tetratricopeptide Repeat-Like Fold and Provides Insights Into Pp2A Regulation.
Biochemistry, 46:8807-, 2007

PubMed Abstract: Physiological functions of protein phosphatase 2A (PP2A) are determined via the association of its catalytic subunit (PP2Ac) with diverse regulatory subunits. The predominant form of PP2Ac assembles into a heterotrimer comprising the scaffolding PR65/A subunit together with a variable regulatory B subunit. A distinct population of PP2Ac associates with the Tap42/alpha4 subunit, an interaction mutually exclusive with that of PR65/A. Tap42/alpha4 is also an interacting subunit of the PP2Ac-related phosphatases, PP4 and PP6. Tap42/alpha4, an essential protein in yeast and suppressor of apoptosis in mammals, contributes to critical cellular functions including the Tor signaling pathway. Here, we describe the crystal structure of the PP2Ac-interaction domain of Saccharomyces cerevisiae Tap42. The structure reveals an all alpha-helical protein with striking similarity to 14-3-3 and tetratricopeptide repeat (TPR) proteins. Mutational analyses of structurally conserved regions of Tap42/alpha4 identified a positively charged region critical for its interactions with PP2Ac. We propose a scaffolding function for Tap42/alpha4 whereby the interaction of PP2Ac at its N-terminus promotes the dephosphorylation of substrates recruited to the C-terminal region of the molecule.

PubMed: 17616149
DOI: 10.1021/BI7007118

Experimental method

X-RAY DIFFRACTION (1.8 Å)