... extracellulardomain. The segments correspond, in fact, with some of the a-amylase family CSRs, namely the b-strandsb2, b3, b4 and b8 of the (b ⁄ a)8barrel domain, and forrBAT also with the short stretch ... the lack of domain B protruding out of the TIM barrel in the place of loop 3 connecting the b3-strand to the a3-helix [9,21]. Sharing domain B by rBATs and GH13 enzymes, and especially the sequence of ... between four and seven conservedsequence regions (CSRs) covering mainly the b-strands of the catalytic TIM barrel [3,11–13]. Of the three GHfamilies of the clan GH-H, it was the family GH13that...