Fig. 2.
The pore of MOMP. (a) The surface of MOMP is colored by electrostatic charge calculated in CCP4MG [21]. The structure has the same orientation as in Fig. 1a. (b) The structure is colored as in (a), with the constriction zone circled. The structure on the left is the same orientation as in Fig. 1b; the structure on the right has been rotated 180° (in effect, looking from the periplasm through the membrane to outside the cell). (c) MOMP trimer viewed from outside the cell; the structure has the same orientation as in Fig. 1c. (d) A detailed view of the charged amino acids at the constriction zone; the view is from outside the cell and the same as in Fig. 1b. The Ca2 + ion, which has been omitted for clarity, is bound to Glu155.