Figure 5. Reconstruction of Subtype I-C/Dvulg Cascade complex.
(A) Superose 6 SEC elution profile of the B. halodurans Cascade complex reconstituted from coexpressing Csd1, Csd2, Cas5d, and crRNA in E. coli. The molecular weight is ~400 kDa as compared to the MW standards. Analysis of the fractions in panel (A) was done using (B) Coomassie blue-stained SDS-PAGE gel or (C) SYBR-GOLD-stained denaturing gel. Fraction numbers are consistent with those shown in panel (A). (D) Negative staining electron micrograph of the B. halodurans Cascade. (E) Two major species were identified from the 2D classification (odd rows, corresponding raw images were shown underneath in even rows). The smaller complex (bottom two rows) likely lacked the Csd1 subunit (indicated by the arrows on the top two rows). Scale bars correspond to 10 nm. See also Figure S4.