Fig. 5.

The catalytic site. a The residues (green) surrounding the bound trisaccharide (yellow) at the solvent-accessible groove of an individual subunit. A pyruvylated glucuronic acid (orange) is modeled to the reducing end of the bound trisaccharide as the − 1 site. b Superimposition of the catalytic center of the K1 lyase (green) with that of KflA (cyan), a bacteriophage-derived K5 lyase²². c Site-directed mutagenesis analyses of selected candidate residues that are proposed to be involved enzyme catalysis