Fig. 2

Schematic view of the protein 3D-model structures of a cel12B with β-jelly roll topology shown in the gray-ramped illustration. The predicted acid/base catalytic residues, Glu¹⁵⁸ and Glu²⁴⁶, are shown in purple and fuchsia ball and stick representations in distinguishing from that of yellow, blue, green, gold, red, aqua, brown, white, and violet representations for Trp⁵⁶, Tyr⁹², Trp¹⁴², Met¹⁶⁰, Trp¹⁶², Pro¹⁷⁰, Ala¹⁷¹, Ile¹⁹², Trp²⁰⁰, and Phe²⁴⁸ catalytic residues, respectively. b cel8C with α-barrel-fold architecture of six (α/α) helices structure shown as inner and outer layers of pinkish cartoon representations. The predicted catalytic residues, Glu⁵⁵ and Asp²⁴³, are shown in the groove center in green and blue ball and stick representations in distinguishing from that of red and black representations for Tyr²⁴⁴ and Phe³³⁵ catalytic residues, respectively. c peh28 with right-handed β-helical-fold of ten full turns showing the gray-ramped cartoon representation. The predicted catalytic residues, Asp²²⁸, Asp²⁴⁹, Asp²⁵⁰, and His277, are shown in the upper area within the T-loop region with blue, red, purple, and green ball and stick representations in distinguishing from that are shown in the bottom-sided area with yellow, aqua, gold, violet, lime, white, and brown representations for Ser²⁷, Asp²⁸, Ser²⁹, Arg³⁰, Asn²³⁷, Asn²⁶⁵, Asn²⁹⁰ catalytic residues, respectively. Cys¹¹⁵ and Trp¹⁶⁰ residues at the peripheral loop region, and Asn³⁷⁰, Val³⁶⁷, Val³⁶⁸, Trp³⁵¹, and Val³³⁰ at the C-terminus are seen as red, yellow, black, blue, orange, white, and green stick representations, respectively. d Peh28 showing the alignment confidence values with endo-polygalacturonase I protein template of van Pouderoyen et al. [54]. High alignment values are shown in red and yellow representations, while the green displayed areas are of moderate alignment values according to Phyre2-model alignment investigation, [30]. The space-filling representations shown in the side and the center of the T-loop region are of Arg⁹⁶⁺ and the catalytic residues of peh28, respectively. Those residues are at a high degree of alignment with those of polygalacturonase I as indicated by the yellow-colored representation shown in their displayed areas