SAM (sterile alpha motif) domain repeat 1 of AIDA1AB-like proteins is a protein-protein interaction domain. AIDA1AB-like proteins have two tandem SAM domains. They may form an intramolecular head-to-tail homodimer. One of two basic motifs of the nuclear localization signal (NLS) is located within helix 5 of SAM2 (motif HKRK). This signal plays a role in decoupling of SAM2 from SAM1, thus facilitating translocation of this type proteins into the nucleus. SAM1 domain has a potential phosphorylation site for CMGC group of serine/threonine kinases. SAM domains of the AIDA1-like subfamily can directly bind ubiquitin and participate in regulating the degradation of ubiquitinated EphA receptors, particularly EPH-A8 receptor. Additionally AIDA1AB-like proteins may participate in the regulation of nucleoplasmic coilin protein interactions.
Jiyao W et al.(2023). "The conserved domain database in 2023.",