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8365728 
Journal Article 
High substrate specificity of ipsdienol dehydrogenase (IDOLDH), a short-chain dehydrogenase from Ips pini bark beetles 
Figueroa-Teran, R; Pak, H; Blomquist, GJ; Tittiger, C 
2016 
Yes 
Journal of Biochemistry
ISSN: 0021-924X
EISSN: 1756-2651 
160 
3 
141-151 
English 
Ips spp. bark beetles use ipsdienol, ipsenol, ipsdienone and ipsenone as aggregation pheromone components and pheromone precursors. For Ips pini, the short-chain oxidoreductase ipsdienol dehydrogenase (IDOLDH) converts (-)-ipsdienol to ipsdienone, and thus likely plays a role in determining pheromone composition. In order to further understand the role of IDOLDH in pheromone biosynthesis, we compared IDOLDH to its nearest functionally characterized ortholog with a solved structure: human L-3-hydroxyacyl-CoA dehydrogenase type II/ amyloid-β binding alcohol dehydrogenase (hHADH II/ABAD), and conducted functional assays of recombinant IDOLDH to determine substrate and product ranges and structural characteristics. Although IDOLDH and hHADH II/ABAD had only 35% sequence identity, their predicted tertiary structures had high identity. We found IDOLDH is a functional homo-tetramer. In addition to oxidizing (-)-ipsdienol, IDOLDH readily converted racemic ipsenol to ipsenone, and stereo-specifically reduced both ketones to their corresponding (-)-alcohols. The (+)-enantiomers were never observed as products. Assays with various substrate analogs showed IDOLDH had high substrate specificity for (-)-ipsdienol, ipsenol, ipsenone and ipsdienone, supporting that IDOLDH functions as a pheromone-biosynthetic enzyme. These results suggest that different IDOLDH orthologs and or activity levels contribute to differences in Ips spp. pheromone composition. © 2016 The Authors 2016. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved. 
ipsdienol; ipsenol; monoterpene; pheromone; short-chain dehydrogenase