Comparison of MJ0391 with MT0146/CbiT. (a) Stereo view of the superposition of MJ0391 (light green) on MT0146/CbiT (red), for all Cα-atoms corresponding to one subunit of the MT0146/CbiT tetramer (PDB ID: 1L3I). (b) The AdoHcy binding site region (stereo view). The interacting residues and the AdoHcy molecule (shown as ‘SAH’ in the figure) of the MT0146/CbiT complex are colored grey & cyan, respectively. The equivalent predicted interacting residues in MJ0391 are yellow. The Tyr65 residue is modeled as Ala, since the electron density corresponding to its side chain was not visible. (c) Electrostatic surface potential of the MJ0391 tetramer. The surfaces are colored blue and red for positive and negative electrostatic surface potentials, denoting less than -15 and greater than +15 K
bT, respectively, where K
b is the Boltzmann constant and T is the temperature. The yellow and green arrows indicate the putative precorrin and AdoMet binding pockets, respectively. The surface potential was calculated with the software APBS incorporated in the PyMOL program (Schrödinger, LLC.).