SAM (sterile alpha motif) domain of DGK-eta subfamily proteins is a protein-protein interaction domain. Proteins of this subfamily are multidomain diacylglycerol kinases. The SAM domain is located at the C-terminus of two out of three isoforms of DGK-eta protein. DGK-eta proteins participate in signal transduction. They regulate the level of second messengers such as diacylglycerol and phosphatidic acid. The SAM domain of DCK-eta proteins can form high molecular weight homooligomers through head-to-tail interactions as well as heterooligomers with the SAM domain of DGK-delta proteins. The oligomerization plays a role in the regulation of the DGK-delta intracellular localization: it is responsible for sustained endosomal localization of the protein and resulted in negative regulation of DCK-eta catalytic activity.
Comment:SAM domains of DGK delta1 proteins interact to each other in head-to-tail manner (end-helix (EH) surface interacts with mid-loop (ML) surface).
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