Crystal structure of the Saccharomyces cerevisiae monoglyceride lipase Yju3p

• DOI: 10.1016/j.bbalip.2016.02.005
• Publication Date: 2016-02-09T07:16:29Z
• Authors: Philipp Aschauer; Srinivasan Rengac...; Joerg Lichtenegger; Matthias Schittmayer; Krishna Mohan Pad...; Nicole Mayer; Rolf Breinbauer; Ruth Birner-Gruen...; Christian C. Gruber; Robert Zimmermann; Karl Gruber; Monika Oberer
• Keywords: 0301 basic medicine; Saccharomyces cerevisiae Proteins; Protein Conformation; Substrate specificity; Monoacylglycerol lipase; Molecular Dynamics Simulation; Catalysis; Substrate Specificity; Lipase–substrate-complex; Structure-Activity Relationship; 03 medical and health sciences; Cloning, Molecular; Molecular Biology; Binding Sites; Crystal structure; Hydrolysis; Cell Biology; Lipase cap; Monoacylglycerol Lipases; Recombinant Proteins; Monoglyceride lipase; Mutation; Mutagenesis, Site-Directed; Monoglycerides; Crystallization; Protein Binding

Monoglyceride lipases (MGLs) are a group of α/β-hydrolases that catalyze the hydrolysis of monoglycerides (MGs) into free fatty acids and glycerol. This reaction serves different physiological functions, namely in the last step of phospholipid and triglyceride degradation, in mammalian endocannabinoid and arachidonic acid metabolism, and in detoxification processes in microbes. Previous crystal structures of MGLs from humans and bacteria revealed conformational plasticity in the cap region of this protein and gave insight into substrate binding. In this study, we present the structure of a MGL from Saccharomyces cerevisiae called Yju3p in its free form and in complex with a covalently bound substrate analog mimicking the tetrahedral intermediate of MG hydrolysis. These structures reveal a high conservation of the overall shape of the MGL cap region and also provide evidence for conformational changes in the cap of Yju3p. The complex structure reveals that, despite the high structural similarity, Yju3p seems to have an additional opening to the substrate binding pocket at a different position compared to human and bacterial MGL. Substrate specificities towards MGs with saturated and unsaturated alkyl chains of different lengths were tested and revealed highest activity towards MG containing a C18:1 fatty acid.