Fig. 3.

Three-dimensional structure of PomAB constructed from single-particle analysis. (A) Structure viewed parallel to the membrane plane. Top and bottom correspond to the periplasmic and cytoplasmic sides of the membrane, respectively. (B) The same structure as in panel A but rotated by 90° around the vertical (2-fold) axis. (C) Structure viewed from the periplasm. Subdomains are labeled 1 to 4. (D) Three-dimensional structure of a PomAB mutant with the PG-binding domain deleted (PomABΔC) (56) shown in the solid density in blue. The magenta net corresponds to the solid density of the wild-type PomAB in panels A to C. Arrows in A and C indicate the shoulder of one arm domain. The contour level of the solid densities in blue is ∼1.8 σ and that of the nets in cyan is ∼1.5 σ. The counter-level of the nets in panels A to C corresponds to ∼100% volume recovery based on a molecular mass of ∼180 kDa for the complex. Scale bar, 25 Å.