3bq7
From Proteopedia
SAM domain of Diacylglycerol Kinase delta1 (E35G)
Overview
The diacylglycerol kinase (DGK) enzymes function as regulators of intracellular signaling by altering the levels of the second messengers, diacylglycerol and phosphatidic acid. The DGK delta and eta isozymes possess a common protein-protein interaction module known as a sterile alpha-motif (SAM) domain. In DGK delta, SAM domain self-association inhibits the translocation of DGK delta to the plasma membrane. Here we show that DGK delta SAM forms a polymer and map the polymeric interface by a genetic selection for soluble mutants. A crystal structure reveals that DGKSAM forms helical polymers through a head-to-tail interaction similar to other SAM domain polymers. Disrupting polymerization by polymer interface mutations constitutively localizes DGK delta to the plasma membrane. Thus, polymerization of DGK delta regulates the activity of the enzyme by sequestering DGK delta in an inactive cellular location. Regulation by dynamic polymerization is an emerging theme in signal transduction.
About this Structure
3BQ7 is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
Regulation of Enzyme Localization by Polymerization: Polymer Formation by the SAM Domain of Diacylglycerol Kinase delta1., Harada BT, Knight MJ, Imai S, Qiao F, Ramachander R, Sawaya MR, Gingery M, Sakane F, Bowie JU, Structure. 2008 Mar;16(3):380-7. PMID:18334213 Page seeded by OCA on Sun May 4 21:00:12 2008
