Figure 5

Representation of three groups of superposed HGPRT structures in the same orientation. Each group is characterized by a different size of the helix α2. (A) Group A includes structures of S. typhimurium (gray), E. coli (green), T. tengcongensis (orange) and T. foetus (magenta). This last organism presents an intermediate size of the α-helix between group A (prokaryotes) and group B (trypanosomatids). (B) Group B includes structures of L. tarentolae (pink) and T. cruzi (blue) presenting an α-helix intermediate in size between prokaryotes and human. (C) Group C includes structures of P. falciparum (yellow), T. gondii (green) and human (blue), showing the larger α-helix. The PDB used are the same as in Figure 3, with the exception of T. foetus (1HGX) and the human (1HMP) structures.