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. Author manuscript; available in PMC: 2016 Dec 14.
Published in final edited form as: Mol Cell. 2000 Oct;6(4):921–929. doi: 10.1016/s1097-2765(05)00087-0

Figure 4. Mutational Analysis of the SNT-1 PTB Domain Interactions with FGFRs or TRKs.

Figure 4

(A) Effects of hFGFR1 point mutations on interactions with the SNT-1 PTB domain as determined by yeast two-hybrid binding assays. Data for peptide mutants are calculated from an average of five independent experiments. Western blot shows BD fusion protein expression of wild-type and mutant hFGFR1 in the yeast cells.

(B) Structure of the SNT-1 PTB domain/hFGFR1 complex shows locations of Arg-63 and Arg-78 (blue) that are essential for binding to the phosphotyrosine in the NPXpY motif. The backbone of the hFGFR1 peptide is shown in green. The distinct β8 strand of the SNT-1 PTB domain is displayed in red.

(C) Structure of the IRS-1 PTB domain in complex with a tyrosine-phosphorylated peptide derived from interleukin-4 receptor (LVIAGNPApYRS, residues 489–499) as determined by NMR (Zhou et al., 1996). The peptide residues are shown in green, and the two key arginine residues (Arg-212 and Arg-227) of the PTB domain that are essential for phosphotyrosine binding are displayed in blue.

(D) Yeast two-hybrid binding studies of the effect of truncation of SNT-1 β8 on its interactions with hFGFR1 and tyrosine-phosphorylated TRKB. The panel framed in red shows the loss of interaction between hFGFR1 and the SNT-1 PTB domain protein lacking the β8 strand. Colony formation on the synthetic complete medium lacking leucine and tryptophan (Leu−, Trp−) illustrates the efficiency of cotransformation with the two plasmids, while growth on the corresponding medium lacking histidine, leucine, and tryptophan (His−, Leu−, Trp−) shows the level of protein-protein interaction.