Crystal structure of L ‐rhamnose 1‐dehydrogenase involved in the non‐phosphorylative pathway of L‐rhamnose metabolism in bacteria

AbstractSeveral microorganisms can utilize L ‐rhamnose as a carbon and energy source through the non‐phosphorylative metabolic pathway, in which L‐rhamnose 1‐dehydrogenase (RhaDH) catalyzes the NAD(P)+‐dependent oxidization of L‐rhamnose to L‐rhamnono‐1,4‐lactone. We herein investigated the crystal structures of RhaDH fromAzotobacter vinelandii in ligand ‐free, NAD+‐bound, NADP+‐bound, and L‐rhamnose‐ and NAD+‐bound forms at 1.9, 2.1, 2.4, and 1.6 Å resolution, respectively. The significant interactions with the 2’‐phosphate group of NADP+, but not the 2 ’‐hydroxyl group of NAD+, were consistent with a preference for NADP+ over NAD+. The C5 ‐OH and C6‐methyl groups of L‐rhamnose were recognized by specific residues of RhaDH through hydrogen bonds and hydrophobic contact, respectively, which contribute to the different substrate specificities from other aldose 1‐dehydrogenases in the short‐chain dehydrogenase/reductase superfa mily.

Source: FEBS Letters - January 22, 2021 Category: Biochemistry Authors: Kentaroh Yoshiwara, Seiya Watanabe, Yasunori Watanabe Tags: RESEARCH LETTER Source Type: research