first cyclin box found in Arabidopsis thaliana B-type cyclins (CycBs) and similar proteins
Plant B-type cyclins (CycBs) correspond to a group of G2/mitotic-specific cyclins that are functionally linked to S- and M-phases of the mitotic cycle, which predicts their involvement also in meiosis. CycBs associate with their partner cyclin-dependent kinases (CDKs) to trigger the kinase activity. They contain two cyclin boxes. This model corresponds to the first one. The cyclin box is a protein binding domain.