Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 1 de 1
Filter
Add more filters










Database
Language
Publication year range
1.
J Biol Chem ; 273(52): 35339-46, 1998 Dec 25.
Article in English | MEDLINE | ID: mdl-9857076

ABSTRACT

SV40 small tumor antigen (small-t) was used as a model to identify structural elements involved in the interactions between regulatory proteins and protein phosphatase 2A (PP2A). Using mutant proteins and synthetic peptides, we identified a small domain within small-t that is a major site for interaction with the dimeric form of PP2A. A series of small-t truncation mutants identified a region surrounding the first of two conserved cysteine clusters that was critical for interaction with PP2A. These mutants also identified additional regions of small-t that contribute to high affinity interaction. Deletion of residues 110-119, which encompass the first cysteine cluster, resulted in a protein that failed to bind to PP2A. Synthetic peptides that contained residues 105-122 of small-t blocked binding of small-t to PP2A. These peptides also inhibited the phosphatase activity of PP2A in a manner analogous to full-length small-t. The active small-t peptides adopt a beta-strand structure that was essential for high affinity interaction with the PP2A dimer. Based on circular dichroism measurements, the same cysteine cluster-containing peptides that bind to PP2A also interact with zinc. Interaction with zinc required the conserved cysteines but was not required for interaction with PP2A.


Subject(s)
Antigens, Polyomavirus Transforming/metabolism , Phosphoprotein Phosphatases/metabolism , Simian virus 40/immunology , Amino Acid Sequence , Antigens, Polyomavirus Transforming/genetics , Binding Sites , Circular Dichroism , Molecular Sequence Data , Mutation , Peptide Fragments/drug effects , Peptide Fragments/metabolism , Phosphoprotein Phosphatases/antagonists & inhibitors , Protein Binding , Protein Conformation , Protein Phosphatase 2 , Sequence Homology, Amino Acid , Zinc/pharmacology
SELECTION OF CITATIONS
SEARCH DETAIL
...