First crystal structure of an NADP + -dependent l-arginine dehydrogenase belonging to the mu-crystallin family.
Kawakami, R., Takami, N., Hayashi, J., Yoneda, K., Ohmori, T., Ohshima, T., Sakuraba, H.(2023) Int J Biol Macromol 249: 126070-126070
- PubMed: 37524275 
- DOI: https://doi.org/10.1016/j.ijbiomac.2023.126070
- Primary Citation of Related Structures:  
8J1C, 8J1G - PubMed Abstract: 
Crystal structures of Pseudomonas veroniil-arginine dehydrogenase (l-ArgDH), belonging to the μ-crystallin/ornithine cyclodeaminase family, were determined for the enzyme in complex with l-lysine and NADP + and with l-arginine and NADPH. The main chain coordinates of the P. veroniil-ArgDH monomer showed notable similarity to those of Archaeoglobus fulgidusl-AlaDH, belonging to the same family, and pro-R specificity similar to l-AlaDH for hydride transfer to NADP + was postulated. However, the residues recognizing the α-amino group of the substrates differed between the two enzymes. Based on a substrate modeling study, it was proposed that in A. fulgidusl-AlaDH, the amino group of l-alanine interacts via a water molecule (W510) with the side chains of Lys41 and Arg52. By contrast, the α-amino group of l-arginine formed hydrogen bonds with the side chains of Thr224 and Asn225 in P. veroniil-ArgDH. Moreover, the guanidino group of l-arginine was fixed into the active site via hydrogen bonds with the side chain of Asp54. Site-directed mutagenesis suggested that Asp54 plays an important role in maintaining high reactivity against the substrate and that Tyr58 and Lys71 play critical roles in enzyme catalysis.
Organizational Affiliation: 
Division of Bioscience and Bioindustry, Graduate School of Technology, Industrial and Social Sciences, Tokushima University, 2-1, Minamijosanjima-cho, Tokushima 770-8513, Tokushima, Japan.