Figure 2

Multiple alignment of amino acid sequences of HXYN2 and xylanase templates. The amino acid sequences of the comparative xylanases were obtained from the non-redundant protein databases using the NCBI BLAST protein server, BLASTp (https://blast.ncbi.nlm.nih.gov/Blast.cgi), from the National Library of Medicine of the USA and were aligned with HXYN2 using the program MEGAv7²⁸. Gaps are identified with a dash. Secondary structures are identified by a red bar (α-helix), navy blue arrows (six β-strands of A β-sheet), and blue arrows (nine β-strands of B β-sheet). The regions with highest sequence similarities are enclosed in a red square, the highly conserved sequence “PSIXG” highlighted in yellow, and the catalytic Glu residues in red. The amino acids marked with an asterisk are involved in FA recognition, with the exception of R148. Strictly conserved residues that participate in xylan binding are shaded in turquoise. Endo-1,4-β-xylanase template PDB structures were downloaded from https://www.rcsb.org/structure with identifiers: 3WP3_A of XylC from Talaromyces cellulolyticus; 2VGD_A of NpXyn11A from Neocallimastix patriciarum; 2VUJ_A of EvXyn11 environmental xylanase expressed in Escherichia coli; 5HXV_E of XylC from Talaromyces cellulolyticus; and 2DCJ_B of XynJ from Bacillus sp. 41 M-1.