1. c.69.1 alpha/beta-Hydrolases many members have left-handed crossover connection between strand 8 and additional strand 9 ! alpha/beta-Hydrolases core: 3 layers, a/b/a; mixed beta-sheet of 8 strands, order 12435678, strand 2 is antiparallel to the rest 1lpa d1lpab2 B:223-229,280-284,287-294,306-315,322-328 1eth d1etha2 A:224-230,281-285,288-295,307-315,323-329 1eth d1ethc2 C:224-230,281-285,288-295,307-315,323-329 1rp1 d1rp1a2 A:223-229,280-285,287-294,306-315,324-328