Before revision: Gln172@N) between the strand A of one sheet and the opposing strand B of the mating sheet   .
After revision: Gln172@N) between the strand A of one sheet and the opposing strand B of the mating sheet . For the neighbouring two single \beta-sheets AB, the two new hydrogen bonds are completely different from the experimental one (an intersheet hydrogen bond between Tyr169 and the backbone carbonyl of Asn171 on an opposing strand) in .