The structural basis for 14-3-3:phosphopeptide binding specificity.
The 14-3-3 family of proteins mediates signal transduction by binding to phosphoserine-containing proteins. Using phosphoserine-oriented peptide libraries to probe all mammalian and yeast 14-3-3s, we identified two different binding motifs, RSXpSXP and RXY/FXpSXP, present in nearly all known 14-3-3 binding proteins. The crystal structure of 14-3-3zeta complexed with the phosphoserine motif in polyoma middle-T was determined to 2.6 A resolution. The bound peptide is in an extended conformation, with a tight turn created by the pS +2 Pro in a cis conformation. Sites of peptide-protein interaction in the complex rationalize the peptide library results. Finally, we show that the 14-3-3 dimer binds tightly to single molecules containing tandem repeats of phosphoserine motifs, implicating bidentate association as a signaling mechanism with molecules such as Raf, BAD, and Cbl.
Yaffe
M B
MB
Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02215, USA.
Rittinger
K
K
Volinia
S
S
Caron
P R
PR
Aitken
A
A
Leffers
H
H
Gamblin
S J
SJ
Smerdon
S J
SJ
Cantley
L C
LC
D048948:14-3-3 Proteins; D018360:Crystallography, X-Ray; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019151:Peptide Library; D010748:Phosphopeptides / Q000378:metabolism*; D010766:Phosphorylation; D010768:Phosphoserine / Q000378:metabolism*; D011485:Protein Binding; D011487:Protein Conformation; D011506:Proteins / Q000737:chemistry / Q000378:metabolism*; D013379:Substrate Specificity; D014446:Tyrosine 3-Monooxygenase
D048948:14-3-3 Proteins; D004791:Enzyme Inhibitors; D019151:Peptide Library; D010748:Phosphopeptides; D011506:Proteins; D010768:Phosphoserine; D014446:Tyrosine 3-Monooxygenase