Multiple sequence alignment and structure comparison of chitinolytic β-N-acetyl-D-hexosaminidases.

<p>(<b>A</b>) Multiple sequence alignments of chitinolytic β-N-acetyl-D-hexosaminidases. They are from <i>Drosophila melanogaster</i> (AAF47881), <i>Fenneropenaeus chinensis</i> (ABB86961), <i>Daphnia pulex</i> (EFX90079), <i>Candida albicans</i> (AAA34346), <i>Arabidopsis thaliana</i> (NP_172050) and <i>Monosiga brevicollis</i> (EDQ91031). The PDB files of OfHex1 (3NSN), SmChb (1QBB) and SpHex (1HP5) were selected as inputted structures. The conserved Val, Glu and Trp residues are shaded. (<b>B</b>) Overlapping of Loop A and Loop B segments of three chitinolytic β-N-acetyl-D-hexosaminidases. They are OfHex1 (3NSN, in blue), SmChb (1QBB, in white) and SpHex (1HP5, in orange). The conserved Val and Trp residues are shown as sticks. The directions of loops are shown by arrows. (<b>C</b>) Overlapping of the +1 subsites in the active pockets of OfHex1 (in blue) in complex with TMG-chitotriomycin (in green) and SmChb (in white) in complex with (GlcNAc)₂ (in pink). Water molecules are shown as red balls and hydrogen bonds are shown as black dashes. The residues of SmChb were grounded.