Molecular characterization of a new evolutionarily conserved nuclear protein e(y)2

Molecular structural and function analyses of the Drosophila melanogaster e nhancer of yellow 2 (e(y)2) gene showed that its product acts as a transcri ption factor and is one of the basic elements of the eukaryotic transcripti on system. The gene is expressed at all stages of D. melanogaster developme nt and consists of a single intron coding for the protein of 101 amino acid residues. The e(y)2 protein does not contain regions homologous to known p roteins. The protein binds with chromatin but not with DNA. On evidence of immune staining, e(y)2 occurs in the nuclei of all D. melanogaster cells. E ach nucleus contains approximately 1.2 x 10(4) molecules of the protein. Im mune staining revealed approximately 200 sites of e(y)2 location on polyten e chromosomes. The protein is evolutionarily conserved: its homologs were f ound in evolutionary distant organisms, such as plants, mammals, and protoz oans. Amino acid sequences of human, rabbit, and mouse e(y)2 are identical to each other.