Fig. 8
From: Bacterial encapsulins as orthogonal compartments for mammalian cell engineering
Encapsulins as genetically encoded markers for cryo-electron tomography (Cryo-ET). a Cryo-ET data from HEK293T cells stably expressing encapsulins together with native ferritin-like cargo proteins (using the dual promoter construct AFLAG;BCDP2A shown in Fig. 6a). 3D rendering showing encapsulins in blue and membranes in gray colors. Scale bar:100 nm. b Example slices from tomograms show encapsulins with and without electron-dense cores from iron-accumulation (treatment with 5 mM FAS for 48 h prior to vitrification). Scale bars:20 nm. c In situ structures (displayed as 2× binned) derived from cryoelectron tomography of nanocompartments assembled in HEK293T cells without (beige), with 0.25 mM FAS and 1 mg/ml human transferrin (cyan) and 5 mM FAS (purple) as compared with the published structure shown in gray (pdb 4PT2; EMDataBank EMD-5917) that was obtained from M. xanthus EncA expressed in E. coli31. The cutaway views of the encapsulins show electron densities indicating the presence of cargo proteins (beige) and additional iron deposition (cyan and purple) as compared to published data from the EncA shell31 that were obtained in the absence of cargo proteins
