Mapping Protein-Protein Proximity in the Purinosome |
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| Authors: | Yijun Deng Jongsik Gam Jarrod B. French Hong Zhao Songon An Stephen J. Benkovic |
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| Affiliation: | From the ‡Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802.;the §Korea Research Institute of Bioscience and Biotechnology, Daejeon 306-809, South Korea, and ;the ¶Department of Chemistry and Biochemistry, University of Maryland, Baltimore, Maryland 21250 |
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| Abstract: | The enzymes in the human de novo purine synthesis pathway were found to form a cellular complex, the purinosome, upon culturing cells in purine-depleted medium (An, S., Kumar R., Sheets, E. D., and Benkovic, S. J. (2008) Science 320, 103–106). Purinosome formation and dissociation were found to be modulated by several factors, including the microtubule network and cell signaling involving protein phosphorylation. To determine whether the pathway enzymes are in physical contact, we probed for the protein-protein interactions (PPIs) within the purinosome with a novel application of the Tango PPI reporter system (Barnea, G., Strapps, W., Herrada, G., Berman, Y., Ong, J., Kloss, B., Axel, R., and Lee, K. J. (2008) Proc. Natl. Acad. Sci. U.S.A. 105, 64–69). We found PPIs among all six enzymes within the pathway and evidence for a core involving the first three enzymes. We also captured purinosomes under both purine-rich and purine-depleted conditions. The results provide additional insights into the transient nature and topography of the purinosome. |
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| Keywords: | Enzymes Protein Engineering Protein-Protein Interactions Purine Structural Biology De Novo Purine Synthesis Cellular Enzyme Complex Purinosome |
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