Which of the followingsequences can form beta-sheet (beta-strand) structure?
D. all of the above
E. only A and B
A beta-sheet is formed when polypeptide chains line up side by side (each known as a beta-strand) with the strands interconnected by hydrogen bonds. These are present in many globular proteins. These protein structures can actually limit the amino acids that can be present in the sheet. For examlple, when these sheets are layered close together, the side chains should be relatively small.