Figure 2.

Detailed views of the GTP binding site in different forms. EF-2 and GMPPCP, GDP, and the side chains of residues which involved in GMPPCP or GDP binding are represented by ribbon and stick models, respectively. The O, N atoms are colored by red and blue, respectively. (A) Structure of GTP-binding site of PhoEF-2-GMPPCP. P-loop, the Switch I and Switch II region, and the G4 and G5 motif (including C atoms of side chains) are colored by red. The C-atoms of GMPPCP are colored by pale blue. (B) Structural comparison of the GTP binding sites of PhoEF-2-Apo (pale yellow), PhoEF-2-D2-GDP (pale green) and protein of PhoEF-2-GMPPCP (red) by superposing domain G. The C atom of GMPPCP and GDP is colored pale blue and pale green, respectively. The residues changed conformation are labeled.