second cyclin box found in Arabidopsis thaliana T-type cyclins (CycTs) and similar proteins
CycTs associate with their partner cyclin-dependent kinases (CDKs) to trigger their kinase activity. CycTs show high sequence similarity with metazoan cyclin-K (CCNK). CycTs contain two cyclin boxes. This model corresponds to the second one. The cyclin box is a protein binding domain.