Recombinant full-length human CDK2 (GenBank Accession No. NM_001798), a.a. 2-298 (end) with N-terminal GST-tag, MW = 61 kDa, and CyclinA2 (GenBank Accession No. NM_001237), a.a. 174-432 (end) with N-terminal His-GST-tags, MW = 75 kDa. Both proteins were coexpressed in a baculovirus Sf9 insect cell expression system.