Fig. 2: Cryo-EM analysis of 2-MIBS-loaded Sg Enc.
From: The biosynthesis of the odorant 2-methylisoborneol is compartmentalized inside a protein shell
a Cryo-EM map of the cargo-loaded Sg Enc shell viewed from the exterior down the two-fold axis of symmetry (left). Cut-away view shown on the right. Density corresponding to the HK97-like shell-forming domain is shown in blue. Externally displayed CBDs are shown in green. Internalized 2-MIBS CLD densities shown in yellow. b Exterior view of a Sg Enc pentamer down the five-fold axis of symmetry highlighting the five-fold pore. c Exterior view of a Sg Enc trimer down the three-fold axis of symmetry. d Exterior (left) and interior (right) view down the two-fold axis of symmetry highlighting the large, elongated two-fold pore. When viewed from the exterior, the CBDs partially occlude the two-fold pore. e Structural model of the Sg Enc shell protomer with characteristic HK97-like domain elements and the CBD highlighted with different colors. MBD: metal-binding domain. f 2D class averages of shell-subtracted 2-MIBS-loaded Sg Enc particles (top). 2D class averages of shell-subtracted empty Sg Enc particles (bottom). While discrete internalized cargo puncta are visible for the cargo-loaded sample, no puncta can be seen in empty shells.
