Ceased Intercellular Communication after Ionophore Treatment Coincides with a Major Structural Rearrangement of the Septal Junction Cap
(A) Shown is a 13.5 nm-thick slice through a cryotomogram (magnified view in box) of the septal area of a CCCP-treated Anabaena filament. SJs are indicated by arrowheads. CM, cytoplasmic membrane; PG, septal peptidoglycan; TM, thylakoid membranes. Bar, 100 nm.
(B–E) Subtomogram averaging of SJs in the CCCP-treated non-communicating “closed” state (B–D) revealed major structural rearrangements in the cap module, compared to the “open” state (E). Shown are surface representations (B and C), and longitudinal and cross-sectional slices (0.68 nm) through the averages (D and E). Sliced positions are indicated in (D) and (E). Bars, 10 nm.
See also Figure S4 and Videos S4 and S5.