STE-Unique

STE-Unique is the residual branch of the STE group, collecting serine/threonine kinases related to the yeast mating-pathway module that do not fall into the STE20, STE11, or STE7 subfamilies. These atypical members retain an STE-type kinase fold but pair it with unusual regulatory domains, and they occupy intermediate or adaptor-like positions in MAPK cascades controlling growth, stress responses, and development. Because individual members differ widely in domain architecture, each is studied on its own terms rather than as a canonical cascade tier. Recombinant STE-Unique kinases are provided for pathway mapping, protein-interaction, and enzymology studies.