The original version of this Article contained errors in Table 2, where the corresponding footnote ‘b’ was omitted in the heading row for ‘β-sandwich (1–139)’, β- ‘barrel 1 (472–583)’ and ‘β-barrel 2 (591–687)’. The correct and incorrect values appear below. Incorrect:β-sandwich^a (1–139)Correct:β-sandwich^a,b (1–139).The original Article has been corrected.