If an ER signal sequence were added to its N-terminus, which structure would the engineered protein adopt

The correct answer would be - structure with both N- terminal and C-terminal in the lumen side.

Explanation:

In eukaryotic cells, the cytosol is the site where protein synthesis takes place which is transported to the endoplasmic reticulum. The protein then moves to the endomembrane vesicle pathway from the endoplasmic reticulum. The transport of the proteins to the different organelles takes place from there as they destined and ultimately secreted from the cell.

In ER such proteins that contain ER signals at the N terminal of the protein are move into the lumen of the endoplasmic reticulum. So, both end N- terminal and C-terminal of the protein ae in the side of the ER lumen

a and c are the answeres