6KTL

Crystal structure of scyllo-inositol dehydrogenase R178A mutant, complexed with NAD and myo-inositol, from Paracoccus laeviglucosivorans

Summary for 6KTL

• Entry DOI: 10.2210/pdb6ktl/pdb
• Descriptor: Scyllo-inositol dehydrogenase with L-glucose dehydrogenase activity, ACETATE ION, NICOTINAMIDE-ADENINE-DINUCLEOTIDE, ... (5 entities in total)
• Functional Keywords: oxidoreductase
• Biological source: Paracoccus laeviglucosivorans
• Total number of polymer chains: 4
• Total formula weight: 168273.36

Authors

Suzuki, M.,Koubara, K.,Takenoya, M.,Fukano, K.,Ito, S.,Sasaki, Y.,Nakamura, A.,Yajima, S. (deposition date: 2019-08-28, release date: 2019-12-25, Last modification date: 2023-11-22)

Primary citation

Suzuki, M.,Koubara, K.,Takenoya, M.,Fukano, K.,Ito, S.,Sasaki, Y.,Nakamura, A.,Yajima, S.
Single amino acid mutation altered substrate specificity for L-glucose and inositol inscyllo-inositol dehydrogenase isolated fromParacoccus laeviglucosivorans.
Biosci.Biotechnol.Biochem., 84:734-742, 2020

PubMed Abstract: inositol dehydrogenase, isolated from (Pl-sIDH), exhibits a broad substrate specificity: it oxidizes - and -inositols as well as L-glucose, converting L-glucose to L-glucono-1,5-lactone. Based on the crystal structures previously reported, Arg178 residue, located at the entry port of the catalytic site, seemed to be important for accepting substrates. Here, we report the role of Arg178 by using an alanine-substituted mutant for kinetic analysis as well as to determine the crystal structures. The wild-type Pl-sIDH exhibits the activity for -inositol most preferably followed by -inositol and L-glucose. On the contrary, the R178A mutant abolished the activities for both inositols, but remained active for L-glucose to the same extent as its wild-type. Based on the crystal structures of the mutant, the side chain of Asp191 flipped out of the substrate binding site. Therefore, Arg178 is important in positioning Asp191 correctly to exert its catalytic activities. IDH: inositol dehydrogenase; LB: Luria-Bertani; : catalyst rate constant; : Michaelis constant; NAD: nicotinamide dinucleotide; NADH: nicotinamide dinucleotide reduced form; PDB; Protein Data Bank; PDB entry: 6KTJ, 6KTK, 6KTL.

PubMed: 31842701
DOI: 10.1080/09168451.2019.1702870

Experimental method

X-RAY DIFFRACTION (1.65 Å)