SAM (sterile alpha motif) domain of CNK (connector enhancer of kinase suppressor of ras (Ksr)) subfamily is a protein-protein interaction domain. CNK proteins are multidomain scaffold proteins containing a few protein-protein interaction domains and are required for connecting Rho and Ras signaling pathways. In Drosophila, the SAM domain of CNK is known to interact with the SAM domain of the aveugle protein, forming a heterodimer. Mutation of the SAM domain in human CNK1 abolishes the ability to cooperate with the Ras effector, supporting the idea that this interaction is necessary for proper Ras signal transduction.
Structure:3BS5, Human/Drosophila, SAM_CNK2/SAM_HYP dimer, contacts at 4A.
Comment:The end-helix (EH) surface of the SAM domain of human CNK2 protein interacts with the mid-loop (ML) surface of the SAM domain of Drosophila HYP (or aveugle) protein.
Jiyao W et al.(2023). "The conserved domain database in 2023.",