FIG. 5.

Amino acid exchanges in BphA1 variants exhibiting novel substrate specificities. Segments (I to III) of major importance for interaction with CB substrates are shown. Positions of the first and last residues in each segment are indicated at the top. Subsegments to which AA exchanges were targeted are boxed. The WT sequence is given in the top row. Below, sequences are grouped according to their detection in the CB screen. The respective CBs are given at the right margin. Exchanges of residues are highlighted by inverse colors. The unintended substitution of BphA1-MZ13 at position 305 is also indicated. Designations of subunits harboring only single AA substitutions are underlined.