Structure of the C-terminal phosphotyrosine interaction domain of Fe65L1 complexed with the cytoplasmic tail of amyloid precursor protein reveals a novel peptide binding mode.
Fe65L1, a member of the Fe65 family, is an adaptor protein that interacts with the cytoplasmic domain of Alzheimer amyloid precursor protein (APP) through its C-terminal phosphotyrosine interaction/phosphotyrosine binding (PID/PTB) domain. In the present study, the solution structures of the C-terminal PID domain of mouse Fe65L1, alone and in complex with a 32-mer peptide (DAAVTPEERHLSKMQQNGYENPTYKFFEQMQN) derived from the cytoplasmic domain of APP, were determined using NMR spectroscopy. The C-terminal PID domain of Fe65L1 alone exhibits a canonical PID/PTB fold, whereas the complex structure reveals a novel mode of peptide binding. In the complex structure, the NPTY motif forms a type-I beta-turn, and the residues immediately N-terminal to the NPTY motif form an antiparallel beta-sheet with the beta5 strand of the PID domain, the binding mode typically observed in the PID/PTB.peptide complex. On the other hand, the N-terminal region of the peptide forms a 2.5-turn alpha-helix and interacts extensively with the C-terminal alpha-helix and the peripheral regions of the PID domain, representing a novel mode of peptide binding that has not been reported previously for the PID/PTB.peptide complex. The indispensability of the N-terminal region of the peptide for the high affinity of the PID-peptide interaction is consistent with NMR titration and isothermal calorimetry data. The extensive binding features of the PID domain of Fe65L1 with the cytoplasmic domain of APP provide a framework for further understanding of the function, trafficking, and processing of APP modulated by adapter proteins.
Li
Hua
H
Systems and Structural Biology Center, RIKEN Yokohama Institute, 1-7-22 Suehiro-cho, Tsurumi, Yokohama 230-0045, Japan.
Koshiba
Seizo
S
Hayashi
Fumiaki
F
Tochio
Naoya
N
Tomizawa
Tadashi
T
Kasai
Takuma
T
Yabuki
Takashi
T
Motoda
Yoko
Y
Harada
Takushi
T
Watanabe
Satoru
S
Inoue
Makoto
M
Hayashizaki
Yoshihide
Y
Tanaka
Akiko
A
Kigawa
Takanori
T
Yokoyama
Shigeyuki
S
D020816:Amino Acid Motifs / Q000502:physiology; D016564:Amyloid beta-Protein Precursor / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D000818:Animals; D051379:Mice; D009419:Nerve Tissue Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D019906:Nuclear Magnetic Resonance, Biomolecular; D009687:Nuclear Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D010455:Peptides / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding / Q000502:physiology; D017510:Protein Folding; D020836:Protein Structure, Quaternary / Q000502:physiology; D017434:Protein Structure, Tertiary / Q000502:physiology
D016564:Amyloid beta-Protein Precursor; C486243:Apbb1 protein, mouse; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D010455:Peptides