The molecular basis of FHA domain:phosphopeptide binding specificity and implications for phospho-dependent signaling mechanisms.
Forkhead-associated (FHA) domains are a class of ubiquitous signaling modules that appear to function through interactions with phosphorylated target molecules. We have used oriented peptide library screening to determine the optimal phosphopeptide binding motifs recognized by several FHA domains, including those within a number of DNA damage checkpoint kinases, and determined the X-ray structure of Rad53p-FHA1, in complex with a phospho-threonine peptide, at 1.6 A resolution. The structure reveals a striking similarity to the MH2 domains of Smad tumor suppressor proteins and reveals a mode of peptide binding that differs from SH2, 14-3-3, or PTB domain complexes. These results have important implications for DNA damage signaling and CHK2-dependent tumor suppression, and they indicate that FHA domains play important and unsuspected roles in S/T kinase signaling mechanisms in prokaryotes and eukaryotes.
Durocher
D
D
Wellcome Trust/Cancer Research Campaign Institute of Cancer and Developmental Biology and Department of Zoology University of Cambridge CB2 1QR, Cambridge, United Kingdom.
Taylor
I A
IA
Sarbassova
D
D
Haire
L F
LF
Westcott
S L
SL
Jackson
S P
SP
Smerdon
S J
SJ
Yaffe
M B
MB
D048948:14-3-3 Proteins; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001120:Arginine / Q000235:genetics / Q000378:metabolism; D001665:Binding Sites; D018797:Cell Cycle Proteins; D064447:Checkpoint Kinase 2; D003460:Crystallization; D018360:Crystallography, X-Ray; D051858:Forkhead Transcription Factors; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D009687:Nuclear Proteins / Q000737:chemistry*; D019151:Peptide Library; D010748:Phosphopeptides / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D010769:Phosphothreonine / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D025941:Protein Interaction Mapping; D011494:Protein Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D013379:Substrate Specificity; D014157:Transcription Factors / Q000737:chemistry*; D014446:Tyrosine 3-Monooxygenase / Q000737:chemistry / Q000378:metabolism; D018909:src Homology Domains
D048948:14-3-3 Proteins; D018797:Cell Cycle Proteins; D051858:Forkhead Transcription Factors; D009687:Nuclear Proteins; D019151:Peptide Library; D010748:Phosphopeptides; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D010769:Phosphothreonine; D001120:Arginine; D014446:Tyrosine 3-Monooxygenase; D011494:Protein Kinases; D064447:Checkpoint Kinase 2; C578634:CHEK2 protein, human; D017346:Protein Serine-Threonine Kinases; C067022:RAD53 protein, S cerevisiae