Figure 1

Structural comparison of TrmIs. A The electrostatic surfaces of each TrmI protein were determined using PYMOL/APBS and are colored by the electrostatic potential. The values of surface potential range from -72 kT/e (red) to +72 kT/e (blue). a _MtTrmI b _TtTrmI c _TmTrmI d _AaTrmI e _PaTrmI. B Stereoview of the tetrameric architecture of _AaTrmI with the SAM ligand in red sticks. The structure is shown with a 45 degree rotation around the vertical symmetry axis compared to Figure 1A. C Closer view showing the tetrameric interface in two orthogonal orientations. The main secondary structure elements are labeled. D Stereo view of the superimposition of the monomer from the six TrmI structures. The Cαs of residues 85 to 263 corresponding to the C-terminal domain (_TmTrmI numbering) are superposed. _PaTrmI (PDB code 3MB5), _AaTrmI, _HsTrmI, _MtTrmI, _TmTrmI and _TtTrmI are drawn in green, cyan, yellow, pink, orange and purple, respectively, and SAM in red sticks. The N-and C-termini are indicated by the letters N and C, respectively. E View of one monomer of _PaTrmI (PDB code 3MB5) labeled with the secondary structure elements and with the polypeptide chain colored according to the B-factors (low B-factor in blue, high B-factor in red).