DNA-dependent protein kinases (DNA-PK) play a role in the repair of double-strand DNA breaks and in the process of V(D)J recombination during lymphoid development. By EST database searching for sequences homologous to the DNA-PK gene KIP/CIB and 5-prime RACE, Seki, N et al. isolated a full-length cDNA, which they designated as KIP2, from a human fetal brain cDNA library. KIP2 encodes a deduced 187aa protein with a predicted molecular mass of 22kD. The KIP2 protein shares 46%, 39%, and 30% sequence identity with the calcium-binding proteins KIP/CIB, calcineurin B and calmodulin respectively. KIP2 contains two EF-hand motifs and a helix-loop-helix motif involved in coordinating the calcium ion, indicating that KIP2 may also bind calcium. KIP2 is ubiquitously expressed in various human tissues.