Ca2+ is the key second messenger in eukaryotes and regulates cell growth,proliferation as well as cell death.Ca2+ signaling in eukaryotes is mediated and coordinated by EF-hand containing calcium binding proteins (CaBPs).Eukaryotic CaBP was first identified in Saccharopolyspora erythraea,a high G+C gram-positive bacterium [1]:later genes encoding CaBPs were found in the genomes of Streptomycetes,but not in other closely related actinomycetes,such as Mycobacteria and Rhodococcus.