[Molecular characteristics of the new evolutionary-conserved nuclear protein e(y)2]

Molecular structural and function analyses of the Drosophila melanogaster enhancer of yellow 2 (e(y)2) gene showed that its product acts as a transcription factor and is one of the basic elements of the eukaryotic transcription system. The gene is expressed at all stages of D. melanogaster development 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 proteins. 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. Each nucleus contains approximately 1.2 x 10(4) molecules of the protein. Immune staining revealed approximately 200 sites of e(y)2 location on polytene chromosomes. The protein is evolutionarily conserved: its homologs were found in evolutionary distant organisms, such as plants, mammals, and protozoans. Amino acid sequences of human, rabbit, and mouse e(y)2 are identical to each other.