The Su(Ste) repeat in the Y chromosome and βCK2tes gene encode predicted isoforms of regulatory β‐subunit of protein kinase CK2 in Drosophila melanogaster

We report an exon-intron structure of the Su(Ste) repeat capable of encoding an isoform of the beta-subunit of protein kinase CK2. The predicted Su(Ste) gene product contains a drastically changed amino acid sequence of the N-terminal fragment as compared to the earlier described bCK2tes gene considered to be an ancestor of the Su(Ste) repeats. The following peculiarities of molecular divergence of the Su(Ste) and betaCK2tes genes are revealed: damages of the autophosphorylation site; usage of an alternative splicing site instead of a damaged one; conservation of the zinc finger domain in spite of local ORF alterations.