[P005] Poster

12:10 PM - 1:00 PM JST(3:10 AM - 4:00 AM UTC)

[P03-381] Identification of a thioesterase from a hyperthermophilic archaeon

○Yu Su¹, Jianqiang Jin², Yuta Michimori¹, Haruyuki Atomi¹ (1. Kyoto Univ. (Japan), 2. Zhejiang Univ. of Technology (Japan))

Keywords:

archaea,thioesterase,enzymology

Thioesterases catalyze the hydrolysis of thioester bonds found in various biological compounds including acyl-CoA and acyl-acyl carrier protein (acyl-ACP). Thioesterases are responsible for the hydrolysis of acyl-CoA or acyl-ACP to release free fatty acids and CoA or ACP in fatty acids biosynthesis. A large number of thioesterases have been characterized from bacteria and eukaryotes. Although it is presumed that they also occur in the archaea based on genome sequence, a thioesterase from archaea has not been experimentally verified. Thermococcus kodakarensis is a hyperthermophilic archaeon that grows optimally at 85℃. It is an obligate anaerobe and heterotroph, and can utilize polysaccharides, organic acids, peptides and amino acids. Amino acid catabolism in this archaeon has been studied in detail, and the final step is the hydrolysis of acyl-CoA catalyzed by various ADP-forming acyl-CoA synthetases. This reaction is important as it is coupled to generation of ATP at the substrate level, and a simple hydrolysis of acyl-CoA by thioesterases would be detrimental to the cell. We carried out a search for genes on the T. kodakarensis genome that might encode a thioesterase, and multiple candidates were identified. Here we report the production, purification and biochemical analysis of a putative thioesterase from this archaeon. Activity towards various acyl-CoA compounds were evaluated and will be presented.