Sequence alignment of conserved sequence motifs I–IV of GH70 glucansucrases, adapted from Leemhuis et al. (2012) and prepared with ESPript (Gouet et al., 1999). NU, nucleophile; A/B, general acid/base; TS, transition-state stabilizer. Residues interacting with subsites −1, +1 and +2 are indicated with black boxes. The three residues from motif IV following the transition-state stabilizer are shown in yellow; the residue immediately following the transition-state stabilizer (Asn1134 in GTFA-ΔN) is indicated by a red triangle. LrGTFA, Lactobacillus reuteri 121 GTFA; LrGTF180, L. reuteri 180 GTF180; LrGTFO, L. reuteri ATC 55730 GTFO; LmDSRS, Leuconostoc mesenteroides NRRL B-512F dextransucrase; LmDSRBCB4, L. mesenteroides B-1299 DSRB CB4 dextransucrase; LmASR, L. mesenteroides B-1355 alternansucrase; SmGTF-SI, Streptococcus mutans glucosyltransferase GTF-SI; SoGTFR, S. oralis ATC10557 glucosyltransferase R; LmDSREG2, L. mesenteroides NRRL B-1299 DSR-E (glucan-binding domain and catalytic domain CD2).