SIMIBI twins in protein targeting and localization.
Signal recognition particle, MinD and BioD (SIMIBI)-type nucleoside triphosphate-binding proteins are an ancient subfamily of nucleotide-binding proteins that serve in a wide range of cellular processes. Notably, this class comprises dimeric ATPases as well as GTPases (SIMIBI 'twins') and a subset of SIMIBI-type proteins, including SRP GTPases, MinD-type ATPases and the Get3 ATPase, is essential to protein targeting and localization. Here, we define common mechanistic principles and differences for these SIMIBI proteins.