FIGURE 3.

Characterization of additional GH5 A4 subfamily genes for dual specificity on glucan and mannan. a, experimental characterization of the endoglucanase (orange) and mannanase (blue) activities of Cel5A_Tma and 10 other genes from GH5 subfamily A4. These genes were selected to broadly cover the A4 subfamily tree and to contain diversity at the specificity-determining positions. Sequence identity to Cel5A_Tma of each gene is depicted with a black line on the plot, and the amino acid identities of the six specificity-determining positions are shown at right. b, the pattern of specificity changes in Cel5C_Cth and Cel5A_Eec from subfamily A4 in comparison with the corresponding mutations in Cel5A_Tma of N20A, E23A, P53A, H96A, E287A, and H95A, respectively (Fig. 2b). Cel5C_Cth and Cel5A_Eec are 29 and 25% identical to Cel5A_Tma, respectively, and closely match specificity patterns observed for Cel5A_Tma except the P72A mutation in Cel5C_Cth. Data in a and b are means from three independent experiments; error bars show S.D.