Figure 3 - full size

 

Figure 3.
FIG. 3. Comparison of the catalytic and secondary phosphotyrosine binding site of PTPL1 and PTP1B. A, a ribbon drawing of the catalytic center of PTPL1 displaying the electron density of the phosphate molecule shown in red. Shown in stick representation are Cys-2408; Asp-2378 in the WPD loop; Gln-2452 from the Q-loop. Also shown are the His-2448, Gln-2221, Gly-2449, and Arg-2444 that make up the secondary phosphotyrosine binding pocket. Superimposed on the structure is a model of how the phosphorylated insulin receptor peptide (ETDY(P)Y(P)R) might interact with PTPL1 based on the structure of this peptide with PTP1B. B, a ribbon drawing of the catalytic center of PTP1B complexed to the phosphorylated insulin receptor peptide (ETDY(P)Y(P)R). Shown in stick representation are Ser-215 (replacing the catalytic cysteine in trapping mutant PTP1B-C215S); Asp-181 in the WPD loop; Gln-262 from the Q-loop. Also shown are the Arg-24, Met-258, Gly-259, and Arg-254 in the secondary phosphotyrosine binding pocket. Note that His-2448 located on the loop between 5 and 6 in PTPL1 is structurally replacing Arg-24 in PTP1B located on the 2'-helix.

The above figure is reprinted by permission from the ASBMB: J Biol Chem (2005, 280, 8180-8187) copyright 2005.