Figure 3.

Structural features of PH1704. (A) Ribbon diagram of PH1704. “H” and “S” refer to helix and strand, respectively. Green, gold, and blue code for β-strand, α-helix, and 3₁₀ helix, respectively. (B) The superposition of the Cα trace of amidotransferase domain of GMP synthetase (green) and that of PH1704 (red). The three members of the catalytic triad, Cys-86, His-181, and Glu-183 of the amidotransferase and Cys-100 and His-101 of PH1704 are labeled. (C) The “nucleophile elbows” in PH1704 (Left) and amidotransferase domain of GMP synthetase (Right).