Fig. 3: Architecture of the DPANN (Microcaldus variisymbioticus ARM-1) S-layer and extended intercellular nanotube.
From: Cell-to-cell interactions revealed by cryo-tomography of a DPANN co-culture system
A Tomographic slice of a DPANN-host assembly showing intercellular tubes (white boxes) between DPANN and its host. B A composite subtomogram average of the intercellular tube between DPANN and its host. The intercellular tube originates in AS-7 and extends into DPANN. Beneath the DPANN S-layer, a large barrel-shaped complex (red arrowheads) forms a platform for the incoming nanotube. The position of the AS-7 S-layer is depicted based on the weak density visible on the average. A schematic of the intercellular tube with distances/diameters is shown on the right (B Created with BioRender.com released under a Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International license). C Tomographic slice of a DPANN cell. Side-view of the S-layer showing distinct structural features (yellow box). Inset showing magnified side-view of the S-layer. Crescent-shaped protein densities are seen extending from the outer S-layer to the cytoplasmic membrane. At least three globular domains are visible (yellow arrowheads, numbered). nm. D Tomographic slice of a DPANN cell with partially detached/peeled off S-layer. Subtomogram averaging of the top views showed sixfold symmetry. Scale bar (A, D) 100 nm, C 25 nm.
