 The study examined the structure of a protein called epa, which is a potential vaccine candidate against entrotoxogenic Escherichia coli, ETC, a diarrhea-causing pathogen. It was found that epa has a unique structure consisting of a right-handed parallel beta helix with two extra helical hairpins and an N-terminal beta strand cap. This structure is highly resistant to chemical and thermal denaturation and can rapidly refold when exposed to heat or chemicals. Additionally, it was discovered that the TPS domain of epa, which is responsible for its secretion from the cell surface, acts as a template for extending the N-terminal beta helix into the C-terminal domains of the TPSA proteins. This suggests that the TPS domain may be important for the proper folding of the entire protein. This article was authored by Clifford Mannyon Tui, James M. Fleckenstein, and Wolf Dieter Schubert.