Supplementary material for Sheppard et al. (2000) Proc. Natl. Acad. Sci. USA 97 (14), 7802-7807.

Fig. 5. Sequence alignment of selected variants of the 10-28 N-glycosylase, arranged according to the secondary structural model. Residues in bold are those that differ from the 10-28 sequence. Clones designated 10-x were obtained after the 10th round of selection for N-glycosylase activity. Clones designated 13-x were obtained after randomization of the 10-28 clone and three additional rounds of selection. Pi and Pi' refer to the 5' and 3' portions, respectively, of a paired element; Ji/j refers to residues joining paired elements i and j. Covariation in support of the model includes replacement of the T31·T76 mismatch within P2 by an A·T pair, replacement of the T52·A85 pair within P3 by a T·G wobble, and replacement of the G104·T111 wobble within P4 by a C·G pair.