The crystal structure of an HSL-homolog EstE5 complex with PMSF reveals a unique configuration that inhibits the nucleophile Ser144 in catalytic triads.
Nam, K.H., Kim, S.J., Priyadarshi, A., Kim, H.S., Hwang, K.Y.(2009) Biochem Biophys Res Commun 389: 247-250
- PubMed: 19715665 
- DOI: https://doi.org/10.1016/j.bbrc.2009.08.123
- Primary Citation of Related Structures:  
3H17, 3H18 - PubMed Abstract: 
The esterase/lipase family (EC 3.1.1.3/EC 3.1.1.1) represents a diverse group of hydrolases that catalyze the cleavage of ester bonds and are widely distributed in animals, plants and microorganisms. Among these enzymes, hormone-sensitive lipases, play a critical role in the regulation of rodent fat cell lipolysis and are regarded as adipose tissue-specific enzymes. Recently, we reported the structural and biological characterization of EstE5 from the metagenome library [K.H. Nam, M.Y. Kim, S.J. Kim, A. Priyadarshi, W.H. Lee, K.Y. Hwang, Structural and functional analysis of a novel EstE5 belonging to the subfamily of hormone-sensitive lipase, Biochem. Biophys. Res. Commun. 379 (2009) 553-556]. The structure of this protein revealed that it belongs to the HSL-family. Here, we report the inhibition of the activity of the HSL-homolog EstE5 protein as determined by the use of esterase/lipase inhibitors. Our results revealed that the EstE5 protein is significantly inhibited by PMSF. In addition, this is the first study to identify the crystal structures of EstE5-PMSF at 2.4 and 2.5A among the HSL-homolog structures. This structural configuration is similar to that adopted when serine proteases are inhibited by PMSF. The results presented here provide valuable information regarding the properties of the HSL-family.
Organizational Affiliation: 
Division of Biotechnology, College of Life Sciences & Biotechnology, Korea University, Seoul 136-701, Republic of Korea.