A functional role identified for conserved charged residues at the active site entrance of lipoxygenase with double specificity

In this study, we used the olive LOX1 with double specificity to investigate the implication of the charged residues R265, R268, and K283 in the orientation of the substrate into the active site. These residues are present in a conserved pattern around the entrance of the active site. Our results show that these residues are involved in the penetration of the substrate into the active site: this positive patch could capture the carboxylate end of the substrate, and then guide it into the active site. Due to its position on α2 helix, the residue K283 could have a more important role, its interaction with the substrate facilitating the motions of residues constituting the “cork of lipoxygenases” or the α2 helix, by disrupting putative hydrogen and ionic bonds. Graphical abstract

Source: Journal of Molecular Catalysis B: Enzymatic - December 6, 2015 Category: Biochemistry Source Type: research