S100 Calcium Binding Protein Z (S100Z)

Using yeast 2-hybrid analysis with the sequence of S100P as bait, Gribenko et al. (2001) identified S100Z from a human prostate cDNA library. S100Z encodes a 99-amino acid protein that shares 57% and 52% sequence identity with S100A1 and S100P, respectively. The 2 EF-hand motifs of S100Z display conservation of amino acids known to be involved in calcium binding. Using circular dichroism, fluorescence spectroscopy, and equilibrium analytical centrifugation, Gribenko et al. (2001) showed that S100Z is a dimeric, predominantly alpha-helical protein that is capable of binding calcium at 2 binding sites with differing affinities. RT-PCR analysis showed highest expression of S100Z in spleen and leukocytes. Expression of S100Z was aberrant in some tumor tissues.